JPH0511078U - Tracking receiver - Google Patents

Abstract

(57) [Summary] [Configuration] Frequency converters 3 and 4 for inputting an RF sum signal and an RF difference signal from an antenna and converting them into an IF sum signal and an IF difference signal, respectively, and supply to these frequency converters. Local oscillation circuit section for generating a local oscillation signal, and AGC amplifiers 7 and 8 for amplifying an IF sum signal and an IF difference signal, respectively.
And a tracking receiver having means for demodulating two output signals of the AGC amplifier and detecting two phase tracking error signals, the local oscillation frequency is made variable by a control signal from the outside to the local oscillation circuit section. Externally controlled local oscillator 26, and variable bandwidth filters 5 and 6 between the frequency converters 3 and 4 and the AGC amplifiers 7 and 8 for switching the transmission bandwidth by external control. . [Effect] Since the frequency and band of the received signal of the user to be captured can be made variable, it is possible to realize a tracking receiver that can handle a large number of users.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention relates to a tracking receiver, and particularly to a high-frequency region such as microwave frequency band. Tracking used to automatically control the antenna that receives the waves to the desired target. Regarding the receiver.

[0002]

[Prior art]

  Conventionally, the structure of a 2-channel type tracking receiver of this type is shown in the block diagram of FIG. Similarly, the RF sum signal for inputting the RF sum signal and the RF difference signal from the antenna (not shown) Input terminal 1, RF difference signal input terminal 2, and local oscillation of this RF sum signal and RF difference signal Frequency conversion for frequency conversion into an IF signal by the local oscillation signal output from the instrument 10. The converters 3 and 4, and the AGC amplifier 7 that amplifies the IF sum signal and the IF difference signal, respectively. , 8 and the output of the AGC amplifier 7 of the IF sum signal are detected, and a predetermined low frequency component is detected. There is an envelope detector 9 to be taken out. This detection signal is an AG of the IF sum signal and the difference signal. The gain is controlled by being fed back to the C amplifier. Further, the difference signal AGC amplifier 8 Phase modulator for phase-modulating the output by the clock signal from the reference signal oscillator 15 11 and the output of the phase modulator 11 are phase demodulated by the output of the AGC amplifier 7 of the sum signal. Then, the first phase detector 12 that outputs the first difference signal of the baseband and the sum signal The output of the AGC amplifier 7 is phase-demodulated through the 90-degree phase shifter 14, The outputs of the second phase detector 13 and the first and second phase detectors 12 and 13 are clocked. Synchronously detect the error signal, detect the error signal, and output the first and second error signals. It is composed of the error signal detection circuits 16 and 17.

[0003]

[Problems to be solved by the device]

  This conventional tracking receiver is a station that converts an RF sum signal and an RF difference signal into an IF signal. Since the frequency of the local oscillator is fixed, it is possible to track only a fixed one-wave received signal. It has the drawback of not being able to. Also, the band limitation of the output signal from the frequency converter is fixed. Therefore, especially when tracking a signal with a narrow transmission bandwidth of the received signal, The noise-to-noise ratio is poor, and the error output sensitivity is reduced, making tracking difficult. .

[0004]

[Means for Solving the Problems]

  The tracking receiver of the present invention inputs the RF sum signal and the RF difference signal from the antenna, A frequency converter for converting each to an IF sum signal and an IF difference signal, and to this frequency converter A local oscillation circuit section for generating a local oscillation signal to be supplied, and the IF sum signal and the difference signal AGC amplifier that amplifies each and the two output signals of this AGC amplifier are demodulated And a means for detecting two phase tracking error signals, External to the local oscillation circuit by changing the local oscillation frequency by an external control signal A controlled local oscillator is provided, and between the frequency converter and the AGC amplifier. It has a variable bandwidth filter that switches the transmission bandwidth by external control.

[0005]

【Example】

  Next, the present invention will be described with reference to the drawings. FIG. 1 shows the tracking of an embodiment of the present invention. It is a block diagram of a receiver. In FIG. 1, the same reference numerals as those in the conventional example of FIG. Have function and function.

[0006]   That is, in the present embodiment, the frequency is controlled by the external control signal 28 as the local signal oscillator. The external control type local oscillator 26 whose number can be changed, and the sum signal from the sum signal AGC amplifier Frequency discriminator 24 that detects the frequency of the signal and outputs it as a frequency control signal, A voltage controlled oscillator 25 whose frequency is varied by a number control signal and an external control type local oscillation The output signal of the voltage regulator 26 and the output signal of the voltage controlled oscillator 25 are frequency-synthesized to generate a local signal. A frequency synthesizer 27 for outputting as an oscillation signal is provided. In addition, the frequency converter 3 , 4 and AGC amplifiers 7, 8 for transmitting IF sum signal and IF difference signal, respectively. Band variable filters 5 and 6 that can switch the band, and control signals from the outside Band input from the control terminal 23 to perform band switching control of the variable band filters 5 and 6. A variable control circuit 22 is provided.

[0007]   Next, the operation of the portion added in this embodiment will be described. First, the local signal oscillator The externally controlled local oscillator 27 is used to set the local oscillation frequency according to the user frequency. There is no correction for frequency fluctuation of user frequency and frequency fluctuation due to Doppler. This is performed by the discriminator 24 and the voltage controlled oscillator 25.

[0008]   On the other hand, when receiving a signal with a narrow transmission band of the received signal, Control is performed and the band of the variable band filters 5 and 6 is switched to a narrower side via the control circuit 22. Bandwidth limitation is performed to improve the S / N ratio and increase the sensitivity of the error signal for better tracking. The tail error can be detected.

[0009]   Note that the user frequency and transmission rate that can be captured are the hardware of the tracking receiver. The tracking frequency range depends on the characteristics of the receiver and the performance of the tracking receiver. The bandwidth is about 20% and the transmission rate is from 1 Mbps to 300 Mbps. Is possible.

[0010]

[Effect of device]

  As described above, the present invention provides an externally controlled local oscillator and an intermediate frequency bandwidth. Variable bandpass filter that can switch the To be equipped with a frequency discriminator and a voltage controlled oscillator to correct frequency fluctuations due to plastic Since the frequency and band of the received signal of the user to be captured can be changed, This has the effect of realizing a tracking receiver that can handle users.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional tracking receiver.

[Explanation of symbols] 1 RF sum signal input terminal 2 RF difference signal input terminal 3,4 frequency converter 5, 6 band variable filter 7,8 AGC amplifier 9 Envelope detector 10 Local oscillator 11 Phase modulator 12 First phase detector 13 Second phase detector 14 90 degree phase shifter 15 Reference signal oscillator 16 First error signal detector 17 Second error signal detector 18, 19 Error signal output terminal 22 Band variable control circuit 23 Control terminal 24 frequency discriminator 25 Voltage controlled oscillator 26 Externally controlled local oscillator 27 frequency synthesizer 28 input terminals

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04B 1/16 J 7240-5K R 7240-5K

Claims (2)

[Scope of utility model registration request] 1. A frequency converter for inputting an RF sum signal and an RF difference signal from an antenna and converting them into an IF sum signal and an IF difference signal, respectively, and a local section for generating a local oscillation signal supplied to this frequency converter. An oscillator circuit section, an AGC amplifier for amplifying the IF sum signal and the difference signal, and
A tracking receiver having means for demodulating two output signals of the C amplifier and detecting two phase tracking error signals,
The local oscillation circuit section is provided with an external control type local oscillator for varying the local oscillation frequency by an external control signal, and the transmission bandwidth is controlled between the frequency converter and the AGC amplifier by external control. A tracking receiver having a variable bandwidth filter to be switched. 2. A frequency discriminator for discriminating frequency by inputting the IF sum signal into the local oscillator circuit portion, and a voltage controlled oscillator whose frequency is controlled by an output signal of the frequency discriminator.
The tracking receiver according to claim 1, further comprising a frequency synthesizer that synthesizes an output signal of the voltage controlled oscillator and an output signal of the externally controlled local oscillator.