CN201113988Y - a receiving device - Google Patents

Abstract

The utility model provides a receiving device, which includes: an antenna and a duplexer, and is characterized in that it also includes: a radio frequency open cable connector connecting the antenna and the duplexer; the radio frequency open cable connector The radio frequency connector end is connected to the antenna, and the open end of the radio frequency open cable connector is connected to the duplexer. The receiving device of the utility model connects the antenna and the duplexer by using a radio frequency open cable, which avoids discontinuity between the radio frequency module and the main board due to welding factors, reduces external interference, and avoids unnecessary transmission loss. The minimum attenuation of the signal between the antenna and the duplexer is ensured, the receiving sensitivity is improved, and the structure is simple and the cost is low.

Description

a receiving device

technical field

The utility model relates to the communication field, in particular to a receiving device.

Background technique

Receiving sensitivity is to test the ability of the base station receiver to receive weak signals. It is a decisive technical indicator that restricts the uplink distance of the base station. It is also one of the technical indicators required by the air interface standard in the RCR STD-28 (Radio Control Relay Standard-28) protocol one. Reasonable determination of receiving sensitivity directly determines the performance and feasibility of large base station radio frequency transceivers. Receiving sensitivity refers to the minimum receiving power measured at the antenna port of the user terminal under the condition that the bit error rate (BER) does not exceed a certain value, where the BER is usually taken as 0.01. The receiving sensitivity of the receiver can be derived as follows:

According to the definition of noise figure, the input signal-to-noise ratio should be:

(S/N) _i = N _F (S/N) _o

Among them, _NF is the noise figure, and the input noise power N _i =kTB. When (S/N) _o satisfies that the bit error rate is less than 0.01, that is, the noise threshold, then the power Si of the input signal is the receiving sensitivity:

S _i = kTBN _FSYS (S/N) _o (1)

in:

k: Boltzmann constant (1.38×10-23J/K);

T: absolute temperature (K);

B: noise bandwidth (Hz);

N _FSYS : receiver noise figure;

(S/N) _o : Noise threshold.

k and T are constants, so the receiver sensitivity is expressed in logarithmic form, then:

S _i ＝-174dB _m +10l _g B+N _FSYS +(S/N) _o (2)

For example, for a PHS system with a noise figure of 3dB, its bandwidth is 300KHz, if the system sensitivity is -107dBm, then the noise threshold of the system is:

(S/N) _o ＝174-107-10lg(3×105)-3＝9.2

It can be seen from the above formula that in order to improve the sensitivity of the receiver even if Si is small, we can start from two aspects, one is to reduce the system noise figure, and the other is to make the noise threshold as small as possible.

Noise is the main factor affecting the sensitivity, one is the noise introduced from the antenna to the input circuit of the low noise amplifier (LNA, Low Noise Amplifier) at the front end of the radio frequency module of the receiver; the other is the signal attenuation from the antenna to the LNA input circuit. If the IF and baseband were ideal transformers, attenuation of the front-end signal would not affect sensitivity. But any actual system is non-ideal, so excessive attenuation of the front-end signal will reduce the sensitivity.

Many manufacturers now produce mobile communication terminals in the form that radio frequency modules are welded on the motherboard. The disadvantage of products produced in this way is that when the RF module is welded to the main board, it will inevitably cause signal discontinuity and increase signal attenuation. Moreover, this solution requires that the impedance mismatch caused by welding must be matched again through the antenna matching circuit arranged on the main board before the main board is connected to the antenna. This matching circuit will inevitably bring unnecessary noise and loss. Specifically, FIG. 1 is a schematic diagram of a front-end structure of a receiving device in the prior art. As shown in FIG. 1 , in a receiving device in the prior art, an antenna 101 is connected to a duplexer 103 of a radio frequency module through an antenna matching circuit 102 .

Utility model content

The purpose of this utility model is to provide a receiving device to solve the technical problem of low receiving sensitivity caused by the large signal attenuation loss from the antenna to the duplexer in the receiving device of the prior art.

In order to achieve the above object, the utility model provides a receiving device, including: an antenna and a duplexer, which also includes:

A radio frequency open cable connector connecting the antenna and duplexer;

The radio frequency connector end of the radio frequency open cable connector is connected to the antenna, and the open end of the radio frequency open cable connector is connected to the duplexer.

In the receiving device, the open end of the RF open cable connector is connected to the RF signal line of the duplexer.

In the receiving device, the open end of the RF open cable connector is welded to the duplexer.

The receiving device, wherein, the conductor in the radio frequency coaxial line at the open end of the radio frequency open cable connector is welded to the radio frequency signal line of the duplexer; the outer conductor of the radio frequency coaxial line is grounded .

The receiving device, wherein, the outer conductor of the radio frequency coaxial line is grounded by welding with the ground wire.

The technical effect of the utility model is:

The receiving device of the utility model connects the antenna and the duplexer by using a radio frequency open cable, which avoids discontinuity between the radio frequency module and the main board due to welding factors, reduces external interference, and avoids unnecessary transmission loss. The minimum attenuation of the signal between the antenna and the duplexer is ensured, the receiving sensitivity is improved, and the structure is simple and the cost is low.

Description of drawings

FIG. 1 is a schematic diagram of a front-end structure of a receiving device in the prior art;

FIG. 2 is a schematic structural diagram of a receiving device according to an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

FIG. 2 is a schematic structural diagram of a receiving device according to an embodiment of the present invention. As shown in FIG. 2 , the receiving device of an embodiment of the present invention includes: an antenna 201 , a duplexer 202 , and a radio frequency open cable connector 203 connecting the antenna 201 and the duplexer 202 . Wherein, the radio frequency open cable connector 203 is composed of a radio frequency coaxial cable, and its two ends are respectively: a radio frequency connector end 2031 and an open end 2032; wherein, the radio frequency connector end 2031 is connected to the antenna 201; the open end 2032 is connected to the antenna 201; The duplexer 202 is connected.

Specifically, the radio frequency connector end 2031 may be directly connected to the antenna 201 , or connected to the antenna 201 through a radio frequency connector provided on the antenna that is compatible with the radio frequency connector end 2031 . The specific connection mode between the open end 2032 of the radio frequency open cable connector 203 and the duplexer 202 can be realized by welding the conductor in the radio frequency coaxial line of the open end with the radio frequency signal line drawn from the duplexer, and the The outer conductor of the RF coaxial line at the open end is grounded. Specifically, the radio frequency coaxial cable at the open end is well grounded by welding with the ground wire.

In a specific implementation, only the matching network between the antenna and the duplexer needs to be replaced by a radio frequency open cable connector, including wiring and all components, and the open end of the radio frequency open cable connector and the The duplexer is connected by soldering and connecting its RF connector end to the antenna.

The receiving device of the utility model saves all devices and matching circuits between the antenna and the duplexer, and uses a radio frequency open cable connector to directly connect the antenna and the duplexer, and the signal is received from the antenna and transmitted into the receiving device through a radio frequency cable. The advanced radio frequency receiving system reduces the external interference, avoids unnecessary transmission loss, minimizes the signal loss between the antenna and the duplexer, and improves the receiving sensitivity. Moreover, the method has a simple structure, is easy to implement, and has important popularization significance.

The above is only a preferred embodiment of the utility model, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements and modifications can also be made. These improvements and modifications It should also be regarded as the protection scope of the present utility model.

Claims (5)

1. receiving system comprises: antenna and duplexer, it is characterized in that, and also comprise:

The radio frequency aperture lines cable connector that connects described antenna and duplexer;

The radio frequency connector end of described radio frequency aperture lines cable connector is connected with described antenna, and the openend of described radio frequency aperture lines cable connector is connected with described duplexer.

2. receiving system according to claim 1 is characterized in that, the openend of described radio frequency aperture lines cable connector is connected with the rf signal line of described duplexer.

3. receiving system according to claim 1 and 2 is characterized in that, the openend of described radio frequency aperture lines cable connector welds mutually with described duplexer.

4. receiving system according to claim 2 is characterized in that, the conductor in the radio-frequency (RF) coaxial line of described radio frequency aperture lines cable connector open end welds mutually with the rf signal line of described duplexer; The outer conductor ground connection of described radio-frequency (RF) coaxial line.

5. receiving system according to claim 4 is characterized in that, the outer conductor of described radio-frequency (RF) coaxial line is by welding ground connection with ground wire.

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