HK1167942B - Self-testing transceiver and self-testing method thereof - Google Patents

Description

Self-testing transceiver and self-testing method thereof

Technical Field

The present invention relates to electronic circuits and systems, and more particularly, to a communication circuit and system.

Background

Transceivers are commonly used in communication systems, such as cellular telephones or other mobile communications, to support the transmission and reception of communication signals over a common antenna in a Radio Frequency (RF) manner. Conventional receivers that are part of a transceiver typically utilize several stages to amplify and process the received signal at a predetermined radio frequency reception frequency range. For example, at the receiver "front end," a Low Noise Amplifier (LNA) boosts (boost) the received signal, which is then down-converted from radio frequency to baseband by a mixing stage. In conventional receiver designs, at the "back end" of the receiver, the baseband signal is filtered by a high order Low Pass Filter (LPF) with high additional gain control. Furthermore, in such conventional transceivers, the transmitter typically implements conditioning (conditioning) and front-end amplification of the transmit signal using several processing stages of an open-loop design, and then transmits the transmit signal to a Power Amplifier (PA).

As the consumer demand for mobile communication devices that are smaller, more powerful, and cheaper increases, people are continually seeking ways to make transceivers less expensive and more efficient. Traditionally, these approaches have focused on improving the integration of circuits and other ways of reducing the physical measurables used to characterize transmitters and/or receivers in transceiver systems. However, in addition to layout and bulk considerations, another source of transceiver manufacturing cost is the use of conventional methods for system detection and calibration.

For example, conventional factory inspection and calibration of transceivers, i.e., transmitter and receiver subsystems in the transceiver, is time consuming and requires dedicated external test equipment. In addition, since the resource requirements for implementing factory testing and calibration are largely independent of the technology node used to manufacture the transceiver, the testing time and efficiency of use of the testing equipment are generally not sufficient to meet the ever-decreasing demands for volume, so that conventional production inspection and calibration increasingly significantly limits production cost effectiveness.

Accordingly, there is a need for a self-test transceiver architecture for a mobile device transceiver that overcomes the disadvantages and drawbacks of the prior art.

Disclosure of Invention

The present invention discloses a self-test transceiver apparatus and associated methods, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.

In accordance with one aspect of the present invention,

a self-test transceiver, comprising:

a receiver;

a transmitter comprising a Power Amplifier (PA) and a plurality of transmitter pre-power amplifier stages (pre-PA stages);

the plurality of transmitter pre-power amplifier stages are configured to generate a communication signal at the transceiver frequency, and the receiver is configured to process another communication signal at the transceiver transmit frequency to enable self-testing of the transceiver.

Preferably, wherein the receiver is a compact, low power receiver having a front end producing a front end gain and a back end producing a back end gain, the front end comprising:

a transconductance amplifier for generating digital gain control and outputting an amplified received signal;

a mixer that generates a down-converted signal from the amplified received signal;

a transimpedance amplifier providing gain control for amplifying the downconverted signal to produce a front end output signal;

wherein the front-end gain is substantially greater than the back-end gain.

Preferably, the plurality of transmitter pre-power amplifier stages are in a closed loop configuration.

Preferably, the plurality of transmitter pre-power amplifier stages are configured to provide digital pre-amplification gain control.

Preferably, the plurality of transmitter pre-power amplifier stages comprise power amplification drives configured to provide digital pre-amplification gain control of at least about 80 decibels.

Preferably, the receiver and the plurality of transmitter pre-power amplifier stages are integrated circuits fabricated on a single semiconductor chip.

Preferably, the self-test transceiver comprises a radio frequency transceiver.

Preferably, the self-test transceiver is a multimode transceiver configured to support a plurality of communication modes.

Preferably, the self-test transceiver is part of a mobile communication device.

According to another aspect of the invention, a method for transceiver self-test, the method comprising the steps of:

generating, by a transmitter of the transceiver, a first communication signal at a transmission frequency of the transceiver;

processing the first communication signal by a receiver of the transceiver;

generating, by the transmitter, a second communication signal at a receive frequency of the transceiver; and

processing, by the receiver, a second communication signal;

self-testing of the transceiver is performed through generation and processing of the first and second communication signals.

Preferably, wherein the receiver is a compact, low power receiver having a front end producing a front end gain and a back end producing a back end gain, the front end comprising:

a transconductance amplifier for generating digital gain control and outputting an amplified received signal;

a mixer that generates a down-converted signal from the amplified received signal;

a transimpedance amplifier providing gain control for amplifying the downconverted signal to produce a front end output signal;

wherein the front-end gain is substantially greater than the back-end gain.

Preferably, the plurality of transmitter pre-power amplifier stages are in a closed loop configuration.

Preferably, the plurality of transmitter pre-power amplifier stages are configured to provide digital pre-amplification gain control.

Preferably, the plurality of transmitter pre-power amplifier stages comprise power amplification drives configured to provide digital pre-amplification gain control of at least about 80 decibels.

Preferably, the receiver and the plurality of transmitter pre-power amplifier stages are integrated circuits fabricated on a single semiconductor chip.

Preferably, the self-test transceiver comprises a radio frequency transceiver.

Preferably, the self-test transceiver is a multimode transceiver configured to support a plurality of communication modes.

Preferably, the self-test transceiver is part of a mobile communication device.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

fig. 1 is a block diagram of a self-test transceiver according to one embodiment of the present invention.

Fig. 2 is a block diagram of a compact, low power receiver architecture adapted to implement the self-test transceiver shown in fig. 1, in accordance with one embodiment of the present invention.

Fig. 3 is a block diagram of a transmitter pre-power amplifier stage 3200 capable of efficient digital pre-amplification gain control, suitable for implementation in the self-test transceiver 100 of fig. 1, in accordance with one embodiment of the present invention.

Fig. 4 is a flow diagram of a method of configuring a transceiver for self-test according to one embodiment of the invention.

Detailed Description

The invention discloses a self-test transceiver device and a related method thereof. Although the present invention has been described in relation to particular embodiments thereof, it will be understood that the principles of the invention as defined by the appended claims may be applied beyond the description of particular embodiments of the invention. In addition, specific details are omitted when describing the present invention in order to highlight the inventive aspects of the present invention. These omitted details are within the knowledge of one skilled in the art.

The drawings in the present application and their accompanying detailed description are directed to merely exemplary embodiments of the invention. To maintain brevity, other embodiments which use the principles of the present invention are not specifically described in the present application and are not specifically illustrated by the present drawings.

Fig. 1 is a block diagram of a self-test transceiver in accordance with one embodiment of the present invention that overcomes the disadvantages and drawbacks of the prior art. Referring to fig. 1, self-test transceiver 1000 includes an antenna 1002, input/output routing switches 1003a and 1003b of the transceiver, a duplexer (duplexer)1004, a transmit/receive (T/R) switch 1005, a Power Amplifier (PA)1006 and a self-test transceiver Integrated Circuit (IC) 1010. As further shown in fig. 1, self-test transceiver integrated circuit 1010 includes a receiver 1100, a transmitter pre-power amplifier stage 1200, a Local Oscillator Generator (LOGEN)1028 (the mixer is not shown in fig. 1) for providing a mixer circuit to the interior of receiver 1100 and the transmitter power amplifier pre-stage, and a low dropout linear regulator (regulator)1029 as an exemplary power supply for local oscillator generator 1028. Although not explicitly shown in fig. 1, the transmitter pre-power amplifier stage 1200 includes a plurality of transmit chain processing stages implemented in a closed loop configuration configured to provide accurate, efficient digital pre-gain control.

The transceiver 100 may be considered to comprise a receive part comprising a receiver 1100 and a transmit part comprising a power amplifier 1006 and a transmitter pre-power amplifier stage 1200. Self-test transceiver 1000 may be implemented in (various communication devices) such as a wireless communication device, a mobile phone, a bluetooth device, a computer, a satellite set-top box, a radio frequency transceiver, a Personal Digital Assistant (PDA), or any other system, apparatus, component, module that uses a transceiver in modern electronics. A more specific example is the use of self-test transceiver 1000 in a cellular telephone or other mobile device that communicates by radio frequency. Such as in a mobile device that communicates in a frequency range of about 0.8Ghz to about 2.2 Ghz.

Referring to fig. 2, 3 and 4, which will explain the principles of the self-test transceiver in more detail, in one embodiment, the local oscillation generator 1028 may be configured to extend the respective ranges of the mixing circuits within the receiver 1100 and the transmitter pre-power amplifier stage 1200, to cause the transmitter pre-power amplifier stage 1200 to generate a communication signal at a receive frequency from the self-test transceiver 1000, and to cause the receiver 1100 to process the communication signal at a transmit frequency from the self-test transceiver 1000. Thus, with the advantages resulting from the isolation of the duplexer 1004 and the transmit/receive switch 1005, the transmitter pre-power amplifier stage 1200 can be used to test the receiver 1100, and the receiver 1100 can be used to test the operation of the transmitter pre-power amplifier stage 1200, thus enabling self-testing of the transceiver.

Turning now to fig. 2, fig. 2 is a block diagram of a compact, low power receiver architecture adapted to the self-test transceiver shown in fig. 1, in accordance with one embodiment of the present invention. The compact low power receiver 2100 in fig. 2 corresponds to the receiver 1100 in fig. 1. The compact, low power receiver 2100 includes a receiver front end 2120 and a receiver back end 2130. As shown in fig. 2, receiver front-end 2120 includes a low noise amplifier 2122 including a tunable transconductance amplifier 2123 for generating digital gain control, mixers 2124a and 2124b that work in conjunction with in-phase (I) and quadrature (Q) signals generated by a local oscillator generator (e.g., LOGEN1028 in fig. 1), respectively, and transimpedance amplifiers 2126a and 2126b including respective current-mode buffers 2125a and 2125 b. As shown in fig. 2, receiver back-end 2130 includes second-order low-pass filters (2nd order low-pass filters) 2132a and 2132b, analog-to-digital converters 2140a and 2140b, and digital processors 2150a and 2150b to perform back-end processing of the respective I and Q signals.

As shown in fig. 2, the compact, low power receiver of an embodiment of the present invention generates a significant portion of the overall gain in the form of a front-end gain. That is, the receiver front-end 2120 produces 50dB of the overall receive gain, while the receiver back-end LPF stage, which includes the second-order LPFs2123a and 2123b, produces a relatively small gain contribution, e.g., about 15 dB. Thus, the compact low power receiver 2100 produces approximately twice, or even more, gain at the front end than at the back end.

The received signal is downconverted, for example, by using digital gain control provided by a low noise amplifier 2122 including an adjustable transconductance amplifier 2123, and additional gain control is provided by transimpedance amplifiers 2126a and 2126b including respective current mode buffers 2125a and 2125b to amplify the downconverted signal. The embodiment of fig. 2 enhances the front-end gain of the compact low power receiver 2100 compared to existing receiver designs. The increase in front-end gain produced by a compact low power receiver reduces the dependence on the back-end gain of embodiments of the present invention. This, in turn, reduces the noise requirements of the low pass filter for filtering the receiver back end 2130. Thus, second order low pass filters 2132a and 2132b may be used in receiver back end 2130.

In contrast to the significant difference implemented in fig. 2, at the back end of a conventional receiver, the baseband signal is typically filtered using higher order low pass filters, e.g., fourth and fifth order low pass filters, which produce a significant portion of the overall gain control in a conventional receiver design. In such conventional receivers, for example, the overall gain control provided by the receiver is primarily generated by the receiver back-end having high order low pass filters, which contribute a significant proportion of the gain. Furthermore, due to the stringent requirements imposed on the high order LPFs used in conventional receiver designs, these features typically require the consumption of a large amount of electrical power and occupy a large portion of the area of the receiver.

As communication technologies evolve toward smaller device sizes and lower power consumption constraints, the typical 40 nm technology-like node makes relatively large, high power consumption conventional receiver devices increasingly less desirable. By reducing the dependence on conventional back-end gain, embodiments of the present invention can achieve both compactness (e.g., requiring less circuit area to achieve) and power savings over conventional designs. Thus, for example, in one embodiment as shown in fig. 1, a compact low power receiver 1100, can be integrated with a transmitter pre-power amplifier stage 1200, a local oscillator generator 1028, and a low dropout linear regulator 1029 on an integrated circuit 1010 from a test transceiver, which can be produced on a single semiconductor die using a 40 nanometer process.

Referring to fig. 3, a block diagram of a transmitter pre-power amplifier stage 3200 capable of efficient digital pre-amplification gain control suitable in the self-test transceiver 100 of fig. 1, in accordance with one embodiment of the present invention. In fig. 3, a transmitter pre-power amplifier stage 3200, consistent with the transmitter pre-power amplifier stage 1200 in fig. 1, is part of a self-test transceiver transmitter along with the PA1006 of the above figure.

As can be seen from fig. 3, the transmitter pre-power amplifier stage 3200 and the self-test transmitter 1000 as a whole may be used to support multiple transmission modes and/or multiple transmission frequencies. For example, the transmitter pre-power amplifier stage 3200 may be configured to support a high band transmission frequency of about 1.8GHz to about 2.2GHz and may also support a low band transmission of about 0.8GHz to about 1.1 GHz.

As shown in fig. 3, the transmitter pre-power amplifier stage 3200 comprises a front end comprising a digital module 3212 that transmits the I and Q phase output signals to respective digital-to-analog converters 3222a and 3222b, respectively. Further depicted in fig. 3 is that the transmitter pre-power amplifier stage 3200 includes adjustable low pass filters 3224a and 3224 b. For example, to support both high-band and low-band frequency channels, the transmitter pre-power amplifier stage 3200 includes respective high-band and low-band mixers 3226a, 3226b, which may be implemented in passive circuits. In addition, the transmitter pre-power amplifier stage 3200 includes a high band variable gain controlled power driver 3230a and a low band variable gain controlled power driver 3230b to provide a pre-amplified transmission signal that is output to the power amplifier (the power amplifier is not explicitly labeled in fig. 3). In addition, fig. 3 also shows a transmitter phase locked loop 3227 and a local oscillation generator 3228, and a feedback correction stage 3240, the feedback correction stage 3240 comprising a peak detector 3250 and an analog-to-digital converter 3290 providing digital calibration feedback to the digital block 3212. Although the transmitter phase locked loop 3227 and local oscillation generator 3228 are paired in fig. 3 for clarity of description, in practice a single transmitter 3227 and local oscillation generator 3228 combination may be coupled to the variable gain controlled power amplification driver 3230a and 3230b and may be shared by the respective high band and low band mixers 3226a and 3226 b. Additionally, in one embodiment, LOGEN 3228 may be further shared by a receiver, such as receiver 1100 in fig. 1, and thus may be considered the same as LOGEN1028 in the above-described figures. As is apparent from fig. 3, the transmitter pre-power amplifier stage implements pre-power amplification gain control in a closed loop configuration represented by feedback from the feedback correction stage 3240 to the digital block 3212. Moreover, the transmitter pre-power amplifier stage 3200 is capable of providing digital gain control, wherein at least about 80 db of digital pre-amplification gain control is provided by each of the variable gain controlled power drivers 3230a and 3230 b.

As described above, the embodiment of fig. 3 can support a plurality of communication methods. For example, in one embodiment, a self-test transceiver including the transmitter pre-power amplifier stage 3200 is capable of supporting communication in W-CDMA mode, GSM mode, and EDGE mode. Thus, the transmitter front end power amplifier stage that is part of a self-test transceiver (e.g., transceiver 1000 in fig. 1) may be selectively configured 3200 to support multiple communication modes to provide for communication in the voice band and the data band.

Thus, the transmitter pre-power amplifier stage 3200, and more generally the self-test transceiver 1000, may be configured to support a communication mode employing a quadrature modulation scheme as well as a communication mode employing a polar modulation scheme. For example, the transmission mode in fig. 3 employing quadrature modulation may connect the outputs I and Q of the digital block 3212 to the solid-line signal paths of the variable gain control drivers 3230a and 3230b through respective digital-to-analog converters, tunable LPFs, mixer combinations 3222ab, 3224ab, and 3226 ab. Similarly, a transmission mode employing a polar modulation scheme may connect the digital block 3212 to the dashed signal paths of the variable gain controlled power drivers 3230a and 3230b through a transmitter phase locked loop 3227.

It is noted that the transmitter pre-power amplifier stage signal path in fig. 3 is represented by a simple line, and many of the signals may include paired differential signals. Thus, for example, the I and Q outputs of b digital block 3212 output to mixers 3226a and 3226, mixers 3226a and 3226b, and the output of digital block 3212 output to variable gain control power amplification drives 3230a and 3230b through TXPLL3227, the feedback correction signal fed back to digital block 3212 through analog-to-digital converter 3290, may comprise a differential signal. It is also noted that the internal signal paths of variable gain controlled power drivers 3230a and 3230b, the feedback signals generated by variable gain controlled power drivers 3230a and 3230b to feedback correction stage 3240, and the outputs of 3258a and 3258b of peak detector 3250 are all explicitly represented as differential signals.

Further as shown in fig. 3, the I and Q signal paths provided by digital to analog converters 3222a and 3222b and adjustable low pass filters 3224a and 3224b, respectively, may be shared between high frequency and low frequency transmission modes. Furthermore, the digital block 3212, transmitter phase lock loop 3227, feedback correction stage 3240 including peak detector 3250, analog-to-digital converter 3290 and power amplifier (not shown in fig. 3) may be used in common for various transmission modes and all transmission bands. Thus, a transmitter including a transmitter pre-power amplifier stage 3200 may be characterized as having a compact, space-saving architecture that is capable of well addressing the low-linearity, low-power consumption constraints imposed by the growing transition to 40-nm node (e.g., beyond) process technology.

The operation of the self-test transceiver of fig. 1 is further described in fig. 4, which is a method for implementing a transceiver self-test in accordance with one embodiment of the present invention. Specific details and features that are well known to those of ordinary skill in the art have been omitted from flowchart 400. For example, steps that are well known in the art, include one or more sub-steps, or include special purpose devices or substances, have been omitted. Although steps 410 through 440 of flowchart 400 are sufficient to describe one embodiment of the present invention, other embodiments of the present invention may employ steps different from those of flowchart 400, or steps in addition to or in lieu of those described herein.

Step 410 of flowchart 400 comprises generating, by a transmitter of the transceiver, a communication signal at a transceiver transmit frequency. In connection with fig. 3, step 410 may be considered to be the function provided by the transmitter pre-power amplifier stage 3200. For example, as described above, the power amplifier pre-stage 3200 may generate a high-band transmit frequency communication signal in the frequency range of about 1.9GHz to about 2.2GHz, or a low-band transmit frequency communication signal in the frequency range of about 0.8GHz to about 1.1 GHz.

Continuing with step 420 in fig. 4, step 420 in flowchart 400 includes the transceiver's receiver processing the communication signal at the transmit frequency generated in step 410. In conjunction with fig. 1, step 420 can be implemented by receiver 1100 and local oscillation generator 1028. That is, in conjunction with fig. 1 and 2, the signal bands transmitted by the local oscillator 1028 to the mixers 2124a and 2124b, including the transmit band and the receive band, may be extended to enable a compact, low power receiver 2100 to efficiently process information, such as the communication signals generated by the transmitter pre-power amplifier stage of step 410.

Turning to step 430 of fig. 4, step 430 of flowchart 400 includes generating a communication signal at a transceiver receive frequency by a transceiver transmitter. In connection with fig. 3, step 430 can also be implemented by the transmitter pre-power amplifier stage 3200 as with step 410. For example, in quadrature modulation communication mode of operation, the frequency range that local oscillation generator 3228 transmits to mixers 3226a and 3226b may be extended, thereby enabling transmitter pre-power amplifier stage 3200 to generate a communication signal at the frequency received from test transceiver 1000.

Continuing with step 440 of flowchart 400, step 440 of flowchart 400 includes transceiver receiver processing the received frequency communication signal generated in step 430. In connection with fig. 1, step 440 may be implemented by receiver 1100, which may be understood as part of its normal operation to process the received frequency signal. The self-test transceiver 1000 enables testing of the operation of the transmitter portion including the transmitter pre-power amplifier stage 1200 using the receiver 1100 by performing steps 410 through 440, as well as testing of the operation of the receiver 1100 using the transmitter pre-power amplifier stage 1200. In other words, self-testing of the receive and transmit portions of transceiver 1000 may be accomplished by performing steps 410 through 440 to generate and process communication signals. Also, because transceiver 1000 is configured for self-testing, the time required for factory testing and calibration and the (cost-intensive) contribution of external test equipment are reduced. Therefore, compared with the prior art, the production cost is reduced, and the production efficiency is improved.

Thus, implementing a receiver configured to process communication signals at the transceiver transmit frequency, embodiments of the present invention enable such transceivers to perform self-testing of their transmitter portion. Further, embodiments of the present invention enable transceiver operation from its receive portion by configuring the transmitter to generate a communication signal at the transceiver receive frequency. Thus, the present invention provides a self-test transceiver that reduces the time required for factory testing and calibration and the cost contribution of external instrumentation. The system can therefore be produced more efficiently and cost effectively.

From the above description of the invention it is manifest that various techniques can be used for implementing the principles of the present invention within the scope of the present invention. Moreover, although the present invention has been described with reference to particular embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. The embodiments described above are to be considered in all respects as illustrative and not restrictive. It should also be understood that the invention should not be limited to the particular embodiments described herein but is capable of many rearrangements, modifications, and substitutions without departing from the scope of the invention.

Claims (10)

1. A self-test transceiver, comprising:

a receiver comprising a front-end and a back-end, the front-end being configured to reduce dependence on a back-end gain of the receiver by increasing its front-end gain, the back-end comprising at least one second-order low-pass filter;

a transmitter comprising a power amplifier and a plurality of transmitter pre-power amplifier stages;

the plurality of transmitter pre-power amplifier stages are configured to generate a communication signal at a receive frequency of the transceiver, and the receiver is configured to process another communication signal at a transmit frequency of the transceiver to enable self-testing of the transceiver.

2. The self-test transceiver of claim 1, wherein said receiver is a compact, low power receiver having a front end producing a front end gain, said front end comprising:

a transconductance amplifier for generating digital gain control and outputting an amplified received signal;

a mixer that generates a down-converted signal from the amplified received signal;

a transimpedance amplifier providing gain control for amplifying the downconverted signal to produce a front end output signal;

wherein the front-end gain is greater than the back-end gain.

3. The self-test transceiver of claim 1, wherein said plurality of transmitter pre-power amplifier stages are in a closed loop configuration.

4. The self-test transceiver of claim 1, wherein said plurality of transmitter pre-power amplifier stages are configured to provide digital pre-amplification gain control.

5. The self-test transceiver of claim 1, wherein said plurality of transmitter pre-power amplifier stages comprise power amplification drives configured to provide digital pre-amplification gain control of at least 80 decibels.

6. The self-test transceiver of claim 1, wherein said receiver and said plurality of transmitter pre-power amplifier stages are integrated circuits fabricated on a single semiconductor chip.

7. The self-test transceiver of claim 1, wherein said self-test transceiver comprises a radio frequency transceiver.

8. The self-test transceiver of claim 1, wherein said self-test transceiver is a multimode transceiver configured to support a plurality of communication modes.

9. The self-test transceiver of claim 1, wherein said self-test transceiver is part of a mobile communication device.

10. A method for transceiver self-test, the method comprising the steps of:

generating, by a transmitter of the transceiver, a first communication signal at a transmission frequency of the transceiver;

processing the first communication signal by a receiver of the transceiver, the receiver comprising at least one second order low pass filter;

generating, by the transmitter, a second communication signal at a receive frequency of the transceiver; and

processing, by the receiver, a second communication signal;

performing a self-test of the transceiver through generation and processing of the first and second communication signals,

wherein the receiver comprises a front end and a back end, the front end being configured to reduce dependence on a back end gain of the receiver by increasing its front end gain.