TWI652451B - Multi-system radar for level measurement and method for measuring a fill level - Google Patents

Abstract

The present invention relates to a level radar that can be switched between a pulse-frequency modulated frequency-modulated continuous wave (FMCW) radar method. For example, a radar device includes two separate front ends that are selectively actuatable via a logic control system. After switching to each of the other measurement principles, the evaluation software is adapted accordingly. In this way, the advantageous properties of the two measurement methods may be used in a targeted manner.

Description

Multi-system radar for level measurement and method for measuring fill level

The present invention relates to level measurement. In particular, the present invention relates to an electronic module for a quasi-radar, a level radar including one of the electronic modules of this type, and a frequency-modulated continuous wave (FMCW). The use of a level radar and a pulsed level radar in combination with a switching device and a method for measuring a fill level.

Current level radar devices operate in a specific radar principle in each case. Commercially available devices use pulsed or FMCE radar methods.

US 7,710,125 B2 discloses a pulse radar method in which a reference channel is used. A FMCW radar method is disclosed in DE 198 13 604 A1.

The pulsed level radar device produces a transmission pulse that is transmitted toward the surface of the fill material using a transmission antenna. These pulses are then reflected (at least in part) from the surface of the fill material and possibly from a separate layer and/or container device or interference point between the container base, the different fill media. The reflected transmission pulse is then received by a receiving antenna (which may also be a transmitting antenna) and converted into an intermediate frequency pulse. This is followed by analog/digital conversion and signal processing, which should ultimately deliver the desired measurement.

Another quasi-radar principle is based on the FMCW principle of continuous wave modulation with frequency modulation. The FMCW level radar device does not transmit (discrete) transmission signal pulses, but instead uses a frequency sweep or a frequency ramp to transmit continuous waves from the antenna towards the surface of the fill material. Also in this case, the reflected signal is received by a corresponding receiving antenna and converted into an intermediate frequency signal, It is then fed to a analog/digital converter and downstream signal processing.

Pulse and FMCW radar devices are available for a wide range of applications. The hardware of these two families of radar devices is very different in construction, in particular with respect to the high frequency (HF) front end and its actuated construction. The HF front end consists of their assemblies of radar devices, which directly relate to generating transmission signals and generating intermediate frequency reception signals.

One of the objects of the present invention is to improve the quality of the measurement results in the level measurement using a level radar device.

This goal is achieved by the characteristics of an independent technical solution. Developments of the invention are available from independent technical solutions and the following description.

A first aspect of the present invention provides an electronic module for a quasi-radar, the electronic module including a signal generating device and a switching device. The signal generating device includes a first sub-assembly and a second sub-assembly.

The first subassembly is configured to generate a first FMCW transmission signal to be transmitted by one of the level radar antennas toward a surface of a fill material, and configured to generate an intermediate frequency (IF) receive signal. Here and hereinafter, "generating" an IF received signal means that the radar device receives the reflected transmitted signal and then generates an IF signal from the received signal by frequency conversion.

The second subassembly is configured to generate a second pulse transmission signal that is transmitted by one of the level radars (possibly another antenna) toward the surface of the fill material, and configured to generate source freedom The one of the reflected second transmission signals received by the antenna receives the signal.

The switching device is configured for selective (event driven and/or user driven) to activate the first subassembly and the second subassembly.

In other words, at any given time, one of the two sub-assemblies can be selected and used to measure the fill level.

In an embodiment of the invention, the first sub-assembly includes a first HF front end for generating the first FMCW transmission signal and for generating the corresponding IF reception signal. Likewise, the second subassembly can include a second HF front end for generating the pulsed second transmission signal and for generating the IF received signal.

In an embodiment of the invention, the first subassembly is integrated into the second subassembly. Alternatively, the second subassembly can be integrated into the first subassembly.

In this context, it is possible and possible to provide that a particular portion of the first sub-assembly is also used by the second sub-assembly or vice versa.

In still another embodiment of the present invention, the switching device is configured to selectively activate the first sub-assembly and/or the second sub-assembly in a fixed predetermined time sequence. For example, it may be provided that the two sub-assemblies are alternately activated and deactivated periodically.

In still another embodiment of the present invention, the switching device is configured to activate the first signal according to, for example, an amplitude of the reflected signal of the reflected first transmission signal and/or the reflected second transmission signal a subassembly and/or the second subassembly. Thus, when, for example, the amplitude of the echo signal in the near field of the antenna exceeds a certain value, the electronic module switches from the FMCW method to the pulse method, wherein the first sub-assembly is deactivated and Start the second subassembly.

In the opposite case, when the amplitude of the echo signal of a particular echo (for example, a fill level echo) drops below a certain threshold or below the threshold, the electronic module may The pulse method switches to the FMCW method.

In still another embodiment of the present invention, the switching device is configured to activate the first sub-assembly and/or the second sub-assembly based on a measured fill level.

For example, it can be provided that when the filling level is relatively high, the electronic module is switched from the first sub-assembly to the second in such a manner that the surface of the filling material is in the near field of the antenna. Sub-assembly.

For a low fill level, for example, the electronic module is provided from the second sub total Switch to the first sub-assembly.

In still another embodiment of the present invention, the switching device is configured to activate the first sub-assembly based on the presence of a multiple echo in the reflected second transmission signal.

If the measurement is performed by the pulse method and it is confirmed that there is an unassignable echo (for example, multiple echoes) in the reflected second transmission signal, the electronic module can switch to the FMCW method.

This can be advantageous because in the case of an FMCW radar, multiple reflections can be imaged in the higher IF frequency range, which can then be filtered out.

In still another embodiment of the present invention, the electronic module includes a single digit signal processing device for processing the one of the reflected transmission signals. A analog/digital converter can be provided upstream of the digital signal processing device.

Therefore, both the FMCW intermediate frequency signal (the measurement signal generated from the reflected transmission signal) and the IF pulse signal are both processed by the same signal processing device. For this purpose, both the HF front end of the FMCW system and the HF front end of the pulse system are connected to the digital signal processing device via a analog/digital converter.

Yet another aspect of the present invention provides a level radar comprising an electronic module of the type disclosed above and below.

In still another embodiment of the present invention, the level radar includes a single antenna, the signal generating device is coupled to the single antenna and the single antenna is configured to transmit the transmitted signals and receive the reflected transmitted signals.

Another option is, for example, to provide two separate duplexers, one of which is connected to the HF front end of the FMCW system and the other to the HF front end of the pulse system.

Yet another aspect of the present invention provides for the use of an FMCW level radar and a pulsed level radar in combination for selectively activating the FMCW level radar and one of the pulse level level switching devices.

The two level radars can be separate devices, for example, each comprising a separate antenna and a different digital signal processing system.

It is also provided that each of the two level radars has an additional antenna, but the IF signals generated by the two level radars are processed in a common digital signal processing device.

Yet another aspect of the present invention provides a method for measuring a fill level, wherein a first sub-assembly of one of the signal generating devices of the level radar initially generates an FMCW transmission signal. The FMCW transmission signal is then transmitted toward the surface of a fill material by one of the antennas of the level radar. This signal is then reflected on the surface of the fill material (among others) and the resulting reflected transmission signal is then received by the level radar. A reflected first transmission signal is then received from the received IF received signal derived from the reflected first transmission signal received by the antenna.

Subsequently, a second sub-assembly of the signal generating device is activated, whereby a second pulse form transmission signal is generated by the second sub-assembly and then transmitted through the antenna of the level radar toward the surface of the filling material . The corresponding reflected transmission signal is received by the antenna and then an IF reception signal is generated therefrom.

It is therefore possible to switch between pulse and FMCW radar methods.

Hereinafter, embodiments of the invention are explained with reference to the drawings.

100‧‧‧ quasi-radar/level radar device

101‧‧‧Activity signal/control system/corresponding logic signal/signal/switching device

102‧‧‧Activity signal/control system/corresponding logic signal/signal/switching device

103‧‧‧High frequency front end/corresponding high frequency front end/first subassembly

104‧‧‧Second high frequency front end/high frequency front end/corresponding high frequency front end/second subassembly

105‧‧‧corresponding line/signal line

106‧‧‧corresponding line/signal line

107‧‧‧High frequency switch or coupler/high frequency switcher

108‧‧‧Antenna

109‧‧‧Control system

110‧‧‧individual signal lines

111‧‧‧individual signal lines

112‧‧‧Electronic module/signal processing device/switching device/digital signal processing device

113‧‧‧Electronic module/signal generator

114‧‧‧Antenna/First Antenna

115‧‧‧Antenna/second antenna

200‧‧ ‧ quasi-radar

201‧‧‧Special Transmission Oscillator/Pulse Oscillator

202‧‧‧VCO/Oscillator

203‧‧‧High frequency terminal

204‧‧‧ Coupler / First Coupler

205‧‧‧Transmission amplifier

206‧‧‧Transmission coupler/coupler

207‧‧‧High frequency terminal

208‧‧‧ Coupler/Antenna

209‧‧‧High frequency terminal

210‧‧‧Mixer/reference signal mixer

211‧‧‧Local oscillator amplifier/amplifier

212‧‧‧ splitter

213‧‧‧Local oscillator amplifier

214‧‧‧Local Oscillator Pulse Oscillator

215‧‧‧ Mixer

216‧‧‧ output

217‧‧‧ Mixer output

300‧‧ ‧ quasi-radar

301‧‧‧ Container

302‧‧‧Filling materials

303‧‧‧ Transmission signal

304‧‧‧ Transmission signal

401‧‧‧ steps

402‧‧‧Steps

403‧‧‧Steps

404‧‧‧Steps

405‧‧‧Steps

406‧‧‧Steps

407‧‧‧Steps

408‧‧‧Steps

409‧‧‧Steps

501‧‧‧Commutation switcher

801‧‧‧Local Oscillator Coupler/Coupler

802‧‧‧High frequency terminal

1 shows an assembly of a level radar in accordance with an embodiment of the present invention.

2 shows an assembly of a level radar in accordance with yet another embodiment of the present invention.

3 shows an assembly of a level radar in accordance with yet another embodiment of the present invention.

4 shows an assembly of a level radar in accordance with yet another embodiment of the present invention.

Figure 5 shows a level radar mounted in a container in accordance with yet another embodiment of the present invention.

Figure 6 shows an example of a coupler that can be used in the embodiments of Figures 2, 3 and 4.

Figure 7 is a flow diagram of one of the methods in accordance with one embodiment of the present invention.

Figure 8 shows an assembly of a level radar in accordance with yet another embodiment of the present invention.

Figure 9 shows an assembly of a level radar in accordance with yet another embodiment of the present invention.

The drawings are schematic and not to scale.

In the following description of the drawings, like reference numerals are used in the drawings However, similar or similar elements may also be represented by different component symbols.

1 shows an assembly of a level radar 100 in accordance with an embodiment of the present invention. The level radar includes an electronic module 112, 113 and one or more antennas 108 or 114, 115.

Depending on the application or external factors, it may be advantageous to operate the level radar device 100 in a pulsed mode or in an FMCW mode. In the presence of large interfering echoes or useful echoes, the FMCW radar method has problems in areas around large signals in some cases because the level of noise around the large signal increases in a manner dependent on one of the systems. Therefore, FMCW level radars usually happen to be "blind" in the vicinity of a large signal (reflected transmission signal). This is also applied in the near field of the antenna due to the large leakage signal at the antenna coupling.

Pulse systems do not have this adverse effect. However, the pulse system can reach its sensitivity limit more quickly than the FMCW system. In particular for very small echoes, the FMCW system has advantages over pulse systems in this respect.

The difference between the two systems is also important for multiple reflections. In the pulse method, typically thousands of individual pulses are transmitted per second, and the thousands of individual pulses can be repeatedly transmitted back and forth between the fill material and the antenna within the measurement distance. This can result in an echo signal (IF signal) that cannot be assigned to a reflection on a real object, since the signal transit time is greater than the time that would correspond to the maximum distance. Thus, the multiple reflected echoes can arrive at the antenna along with the primary reflection of a subsequent pulse.

In contrast, in FMCW systems, signals from multiple reflections are formed at higher IF frequencies, which can then be filtered out.

The signal generating means 113 of the level radar shown in Fig. 1 includes an HF front end 103 which produces an FMCW transmission signal. A control system is provided that can activate and deactivate one of the HF front ends 103 by means of the coincident motion signal 101.

Signal generating device 113 also includes a second HF front end 104 that can generate a pulsed form of transmission signal, as is conventional in pulse radar devices. A control system for activating and deactivating the second HF front end 104 and generating an actuation signal 102 is also provided.

The transmission signals generated in this manner are then transmitted from the corresponding HF front ends 103, 104 to the antenna 108, which transmits the transmission signals towards the surface of the fill material via the corresponding lines 105, 106.

Signal lines 105, 106 are coupled to antenna 108 via an HF switch or coupler 107.

For example, the HF switch can be switched via the control system 109 so that in principle the two HF front ends 103, 104 will likely generate the FMCW transmission signal and the pulse transmission signal continuously, but in fact only one of the two signals It is passed to the antenna 108, depending on the setting of the HF switch 107.

However, in many cases, it will be appropriate for the control systems 101, 102 to activate each HF front end 103, 104 only at a given time, at which point the corresponding HF front end will be used for level measurement.

Alternatively, it is also possible to provide two antennas 114, 115, the first antenna 114 being connected to the first HF front end 103 and the second antenna 115 being connected to the second HF front end 104. In this case, no HF switch or coupler 107 is needed.

Subsequently, the transmitted transmission signal is reflected by the surface of the fill material, among other things, and the corresponding reflected transmission signal is received by the antennas 108, 114, 115 and fed to the HF front ends 103, 104 that produce the original transmission signal. The transmission signals received in this manner, corresponding to the HF front ends 103, 104, produce an intermediate frequency signal, as is known in the art. The two HF front ends are connected via a different signal line 110, 111 to a signal processing device 112 having an upstream analog/digital conversion. Therefore, the generated IF signal is initially digitized and subsequently subjected to the signal In order to finally determine the fill level.

Figure 1 correspondingly shows an embodiment with a fully separate front end branch for a pulse system and an FMCW system. Individual role branches are connected to the analog/digital converter.

Thus, the two front ends can be selectively activated by the corresponding logic signals 101, 102 from one of the control systems. The interface for evaluating the electronic device can be an analog/digital converter. After switching to each of the other measurement principles, the evaluation software must be immediately adapted as well as the hardware. Control system 109 is coupled to signal processing device 112 for this evaluation software adaptation.

At this point, it should be noted that all of the control components in the control assembly can be integrated into a single component.

Signals 101 and 102 can be simple logic signals or contain necessary signals specific to the front end, such as clock signals or current/voltage supplies.

FIG. 2 shows yet another embodiment of a quasi-radar 200. In the front end area, there are components that appear in both systems (FMCW system and pulse system). This applies, for example, to an HF mixer (echo channel), an oscillator, and a coupler structure.

Figure 2 shows the layout of a pulse system supplemented by a small extension of one of the FMCW systems. Depending on the principle of measurement, the different components should then be switched on or off.

The details of this embodiment may vary. Alternative embodiments are shown in Figures 3 and 4. For example, a special transfer oscillator 201 (in this case, a VCO) that can operate in both pulsed and FMCW operations can be provided.

Alternatively, one of the pulse oscillators 201 and a single VCO 202 can be selectively operated separately from each other, as shown in Figures 3 and 4. In the embodiment of FIG. 3, a commutating switch 501 is provided that can be switched back and forth between the pulse oscillator 201 and the VCO 202. This commutation switch is not provided in the embodiment of FIG. Here, the respective required oscillators are activated and the other oscillators 202, 201 are deactivated. As for the circuit, the two oscillator signals are brought together via the coupler 204, and the HF terminal 203 is not provided.

For example, the end user can set the measurement principle of the level radar by himself. It can also be provided that the evaluation software determines one or the other measurement principle based on the current echo relationship.

It is also possible to provide a cyclical alternating between the two measurement principles (in other words, in a fixed predetermined time series).

Signal processing can also be configured to be variable. For example, the measurements may be individually determined for each system (FMCW and pulse), or provided, considering the evaluation results derived from the FMCW mode and the pulse mode of the signal processing device (not shown in FIG. 2) to complement each other.

Thus, for example, there may initially be an FMCW measurement followed by a pulse measurement. Two measurements can supply different results, but this can be considered together in an overall assessment. Thus, the measurement results of the FMCW measurements can be used specifically to, for example, identify multiple echoes and low amplitude echoes, while the results of pulse measurements are considered for near field or other high amplitude echoes.

A signal generated by pulse oscillator 201 (which may also operate as a VCO, cf, Figure 2) is fed to one of the split signal couplers 204. In the case of a pulsed operation, one portion is assigned to the transmission channel; the second portion forms the reference channel, and in the case of FMCW operation, this signal is used as one of the LOs for the echo channel mixer.

One of the outputs of the coupler 204 (transmission channel) is directed via a TX amplifier (transmission amplifier) 205 to a transmit coupler 206, the first output of which is coupled to an HF terminal 207. The other outputs are directed to an antenna 108 that transmits a transmission signal to the fill material. The echo channel connected to the antenna 108 also includes a mixer 215 that is coupled to the antenna 108 via a coupler 206 on the one hand and to the splitter 212 on the other hand, and the output 216 of the mixer 215 is transmitted in the middle. The frequency measurement signal (in other words, the reflected transmission signal that has been converted into an intermediate frequency signal).

The reflected transmission signal is received by antenna 108 and then transmitted via coupler 206 to a mixer 215.

A further coupler 208 is coupled to the second output of the first coupler 204. Another coupler The second input of 208 is coupled to an HF terminal 209.

The reference channel mixer is coupled to the upper output of coupler 208. The reference signal (for pulse mode only) is generated in the manner of a mixer 210 positioned in this reference channel, which is supplied with the signal of the pulse oscillator 201 on one side and via the LO amplifier 213 on the other side. The splitter 212 is supplied with a signal of the LO pulse oscillator 214. Mixer output 217 provides an intermediate frequency reference signal. This reference wave tube is not required and is not evaluated for FMCW operation.

Finally, an LO pulse oscillator 214 is provided. The output signal of the LO pulse oscillator 214 is amplified by the LO amplifier (pulse) 213 and fed to the splitter 212. After being amplified by the LO amplifier (FMCW) 211, the second output signal of the coupler 208 is also fed to the splitter 212.

In the case of an FMCW measurement, the LO amplifier (FMCW) 211 is turned on and the LO amplifier (pulse) 213 and the LO pulse oscillator 214 are turned off. The echo channel mixer obtains its LO (local oscillator) signal from transmit oscillator 202 (VCO) or 201 (combined pulse oscillator and VCO) via couplers 204, 208, amplifier 211 and splitter 212. In the case of a pulse measurement, on the contrary, the LO amplifier is turned on/off. In this case, the LO pulse oscillator 214 is turned on again. Thus, the echo channel mixer just as the reference signal mixer 210 now derives its LO signal from the LO pulse oscillator 214.

A special TX oscillator 201 (Fig. 2) that can operate in both pulsed and FMCW operation can be provided.

In yet another embodiment, a pulse oscillator 201 and a VCO 202 (Fig. 3 or Fig. 4) are separately provided and selectively operated.

In other embodiments, a system that does not have a reference channel for pulsed operation is illustrated. The number of couplers and hardware complexity are generally significantly reduced.

Although amplifiers for transmitting signal (TX) and LO signals are shown in the illustrated embodiment, they may not be provided if the oscillator amplitude is sufficient.

Figures 8 and 9 show an embodiment for pulsed operation but without a reference channel.

In the embodiment of FIG. 8, unlike FIG. 2, coupler 208, mixer 210, and splitter 212 are not provided. Instead of the splitter 212, an LO coupler 801 is provided. A first input of the coupler 801 is coupled to the LO amplifier 211 and a second input is coupled to the LO amplifier 213. The first output is coupled to the mixer 215 of the echo channel and the second output is coupled to an HF terminal 802.

In the embodiment of FIG. 9, an LO coupler 801 having a HF terminal 802 and a transmit coupler 206 are also provided. As in FIG. 8, the LO coupler 801 is connected to the LO amplifier 213. It is further connected to the transmit coupler 206. A mixer 215 that transmits an IF echo signal and is coupled to antenna 208 via transmit coupler 206 is positioned at a fourth terminal of LO coupler 801.

FIG. 5 shows a level radar 300 mounted in a container 301 and including an electronic module having a signal generating device 113 and a switching device 112. The electronic module is coupled to an antenna 108 that transmits a transmission signal 303 toward the fill material 302. This transmitted signal is then reflected (at least in part) and the reflected transmitted signal 304 is received by the antenna 108 and passed to the electronic module where it is converted to an intermediate frequency signal, digitized and then subjected to further signal processing.

6 shows four examples of couplers 204, 206, 208, 801 and splitters 212 that can be used in FIGS. 2, 3, 4, 8, and 9. A two-arm branch line coupler (90° hybrid) is shown at the top left and has a three-arm split line coupler (90° hybrid) for larger bandwidth along its side. A ring coupler (mouse diameter, 180° hybrid) is shown at the left bottom and has a double-armed branch line coupler (90° hybrid) in the form of a ring along its side. It is also possible to replace the coupler 206 with a circulator, in which case the HF terminal 207 need not be provided.

Figure 7 is a flow diagram of one of the methods in accordance with one embodiment of the present invention. In step 401, a pulse transmission signal is generated by a subassembly of one of the signal generating devices of one of the quasi-radars. Subsequently, in step 402, the pulse transmission signal is transmitted towards the fill material by means of one of the level radar transmission antennas. In step 403, the reflected transmission signal is received by the antenna And passing the reflected transmission signal to the electronic module, where it can be converted into an IF signal, digitized and subjected to subsequent signal processing. Now activate the signal generating device based on the particular environment (for example, in the form of most recently received echo curves and/or when user intervention occurs and/or as a result of one of the pre-programmed periodic sequences) One of the different sub-assemblies (step 404).

In step 405, the second subassembly produces an FMCW transmission signal that is transmitted via the antenna toward the surface of the fill material in step 406, the FMCW transmission signal being reflected and received again by the antenna. In step 407, one of the reflected transmission signals received by the source free antenna is received from the reflected and received transmission signals. This received signal is then digitized and subjected to an evaluation in step 408. In step 409, another subassembly is deactivated again and the first subassembly is used to continue the measurement.

For the sake of completeness, it should be noted that "comprising" and "having" do not exclude the possibility of other components or steps, and "an" or "a" does not exclude the plural. possibility. It should be further noted that features or steps that have been disclosed with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments disclosed above. Symbols in the scope of patent application should not be considered limiting.

Claims (10)

An electronic module (112, 113) for a quasi-radar (100, 200, 300), the electronic module comprising: a signal generating device (113) comprising: a first sub-assembly (103) , which is used to generate a continuous wave (frequency-modulated continuous) that is modulated by a first frequency of one of the antennas (108, 114, 115) of the level radar (100, 200, 300) toward a surface of a filling material. Wave, FMCW) transmits a signal and is used to generate an IF received signal from the one of the reflected first transmission signals received by the antenna; and a second sub-assembly (104) for generating a bit to be generated by the bit One of the quasi-radars (100, 200, 300) transmits a signal in the form of a second pulse toward the surface of the fill material and is used to generate the reflected second transmission received by the antenna One of the signals IF receives the signal; and a switching device (101, 102, 112) for selectively activating the first sub-assembly and the second sub-assembly; wherein the switching device (101, 102, 112) Configuring to periodically alternately activate the first sub-assembly and the second sub-assembly in a predetermined time sequence; The sub-module further includes a digital signal processing device (112) configured to process the reflected transmission signals, wherein the switching device is configured to determine whether to use the reflected first transmission signal or to use the The second transmission signal is reflected to determine a fill level. The electronic module (112, 113) of claim 1, wherein the first sub-assembly (103) includes a first HF front end for generating the first FMCW transmission signal and for generating the IF reception signal; The second subassembly (104) includes a second transmission signal for generating the pulsed form And a second HF front end for generating one of the IF received signals. The electronic module (112, 113) of claim 1 or 2, wherein the first sub-assembly is integrated into the second sub-assembly. The electronic module (112, 113) of claim 1 or 2, wherein the switching device (101, 102, 112) is configured to echo signal amplitude according to one of the reflected first or second transmitted signals And the first sub-assembly or the second sub-assembly is activated. The electronic module (112, 113) of claim 1 or 2, wherein the switching device (101, 102, 112) is configured to activate the first sub-assembly or the first according to a measured fill level The second sub-assembly. An electronic module (112, 113) as claimed in claim 1 or 2, wherein the switching device (101, 102, 112) is configured to be based on the presence of a multiple echo in the reflected second transmission signal Start the first subassembly. An electronic module (112, 113) as claimed in claim 1 or 2, wherein the switching device (101, 102, 112) is configured to activate the first or second depending on the occurrence of a noise level or sound property Sub-assembly. A level radar (300) comprising an electronic module according to any one of claims 1 to 7. A level radar (300) as claimed in claim 8, wherein the level radar comprises a single antenna (108), the signal generating means (113) is coupled to the single antenna (108) and the single antenna (108) is configured Transmitting the transmission signals and receiving the reflected transmission signals. A method for measuring a fill level, the method comprising the steps of: generating, by a first sub-assembly (103) of one of a signal generating device (113) of one of a quasi-radar (100, 200, 300) a first FMCW transmission signal; with one of the antennas (108, 114, 115) of the level radar (100, 200, 300) Transmitting the first FMCW transmission signal to a surface of the filling material; receiving the first transmission signal reflected on the surface of the filling material; generating an IF receiving signal of the first transmission signal reflected by the antenna; and starting the signal generation a second sub-assembly (104) of the device (113); generating a second pulse form transmission signal by the second sub-assembly; and an antenna (108) of the level radar (100, 200, 300) , 115, 114) transmitting the second transmission signal toward the surface of the filling material; generating an IF receiving signal derived from the reflected second transmission signal received from the antenna; processing the reflected transmission signals and determining whether to use The reflected first transmission signal or the reflected second transmission signal is used to determine a fill level; wherein the first sub-assembly and the second sub-assembly are alternately activated periodically in a predetermined time series.