KR960032931A - Local Oscillators for Satellite Communication Earth Station Systems - Google Patents

Abstract

The present invention relates to a local oscillator used in a frequency conversion device of an earth station in a satellite communication system. Reference frequency refinement means (4) for generating a frequency synchronized with the reference frequency to provide a local oscillator; Frequency generating means (PLO) 5 for generating a frequency synchronized with the output of said reference frequency purification means 4 and supplying it to an external frequency converter 1; Frequency multiplication means (6) for multiplying the frequency by receiving the output of the frequency generating means (5); First frequency synthesizing means (7) for receiving a reference frequency, receiving the output of the frequency multiplying means (6) for synthesizing the frequencies according to an external frequency control command and outputting them externally; And a second frequency synthesizing means (8) for receiving a reference frequency and synthesizing the frequency according to the frequency control command to the outside to maintain the high reliability of small size, light weight, economical efficiency and stable performance. The effect is to make the system smaller and lower the price.

Description

Local Oscillators for Satellite Communication Earth Station Systems

Since this is an open matter, no full text was included.

1 is a configuration diagram of a frequency conversion apparatus to which the present invention is applied;

2 is a block diagram of a local oscillator according to the present invention,

3 is a block diagram of a Ku band frequency synthesizer according to the present invention.

Claims (11)

Reference cleaner 4 for generating a frequency synchronized with a reference frequency input from the outside; Frequency generating means (PLO) (5) for receiving one output of the reference frequency refining means (4) to generate a synchronized frequency and to supply it to an external uplink frequency converter (1); A frequency multiplier (6) for multiplying the frequency by receiving the output of the frequency generating means (5); Receiving a reference frequency from the reference frequency purification means (4), receiving the output of the frequency multiplier (6) synthesizes the frequency according to an external frequency control command to the uplink frequency converter (1) and the external downlink frequency A first frequency synthesizer 7 for supplying the converter 2; And a second frequency synthesizer (8) for receiving a reference frequency from the reference frequency refiner (4) and synthesizing the frequency according to the frequency control command and supplying the frequency to the downlink frequency converter (2). A local oscillator for satellite communication earth station system, characterized in that. 2. The apparatus according to claim 1, wherein said reference frequency refinement means (4) comprises: filtering means for filtering after filtering and removing noise contained in a 10 MHz reference frequency signal during long distance transmission; And a phase locked loop (PLL) for generating a 125 MHz reference frequency signal synchronized with the 10 MHz reference frequency signal. The local oscillator for a satellite communication earth station system according to claim 2, wherein said filtering means comprises a narrow bandwidth crystal filter. 3. The local oscillator for a satellite communication earth station system according to claim 2, wherein the PLL is configured as an edge-triggered digital phase comparator. The satellite communication earth station system according to claim 1, characterized in that the frequency generating means (5) is composed of a phase locked oscillator (PLO) having a loop bandwidth of several 10 MHz so as to generate a 875 MHz signal synchronized with a 125 MHz reference signal. Local oscillator. 2. The frequency multiplying means (6) according to claim 1, characterized in that the frequency multiplying means (6) generates harmonics of 875 MHz by means of a step recovery diode and generates 12250 MHz, which is the 14th harmonic by a band pass filter. Local oscillator for satellite communication earth station system. 2. The second frequency synthesizing means (8) according to claim 1, characterized in that the second frequency synthesizing means (8) generates a 850 to 900 MHz signal synchronized with the 10 MHz reference frequency signal from the reference frequency purification means (4) at intervals of 1 MHz by the frequency control command. Local oscillator for satellite communication earth station system, characterized in that configured. 2. The second frequency synthesizing means (8) according to claim 1, characterized in that the second frequency synthesizing means (8) is configured to generate 873 MHz signals synchronized with the 10 MHz reference frequency signals from the reference frequency purification means (4) at 1 MHz intervals by the frequency control command. A local oscillator for a satellite communication earth station system. 2. The apparatus according to claim 1, wherein the first frequency synthesizing means (7) comprises: voltage controlled oscillation means (VCO) 9 for generating a frequency in accordance with an input voltage; Coupling means (10) for receiving only the frequency of the voltage-controlled oscillation means (9) and combining only part of the signal and passing most of it; First mixing means (11) for receiving and mixing one output of the combining means (10) and the output of the frequency multiplying means (6); Low-pass filtering means (12) for passing only the lower band of the output of the first mixing means (11); First amplifying means (13) for receiving and amplifying the output of the low pass filtering means (12); First power dividing means (19) for dividing and supplying a reference frequency signal input from said reference frequency purifying means (4); Frequency synthesizing means (15) for receiving the divided frequency of the first power dividing means (19) and synthesizing the frequencies according to an external frequency control command; Second mixing means (14) for receiving and mixing the outputs of the first amplifying means (13) and the frequency combining means (15); Band pass filtering means (BPF) 16 for passing a predetermined band of the output of the mixing means 14; Second amplifying means (17) for amplifying the output of said band pass filtering means (16); Phase detection means (18) for detecting a difference by comparing a phase of a frequency output from said first power dividing means (19) and said second amplifying means (17); A loop filter (20) for receiving the output of the phase detection means (18), removing high frequency components, integrating them, and supplying them to the voltage controlled oscillation means (9); Ku-band frequency synthesizer, characterized in that it comprises a second power dividing means (21) for receiving the other output of the coupling means (10) to divide and output to the outside. 10. The Ku band (Ku-) according to claim 9, wherein the voltage controlled oscillation means (VCO) 9 is composed of a micro strip line and a varactor diode using a field effect transistor (FET) to obtain a high output. band) frequency synthesizer. 10. The method of claim 9, wherein the voltage controlled oscillation means (9) receives the output of the loop filtering means (20) and generates a signal of 13.055 to 13.555 MHz in the 500 MHz band synchronized with the reference frequency, 10 outputs the entire signal and the output power 8 dB lower than the output voltage level of the voltage controlled oscillation means (VCO) 9, and the first mixing means (Microwave Mixer) 11 is the coupling means (10). The low-pass filtering means (LPF) 12 mixes an 8 dB low output of the voltage controlled oscillation means 9 output from Of the two sideband components generated by the means 11, only the lower band is passed and outputs a signal of 805 to 1305 MHz, and the first amplifying means (AMP) 13 inputs the output of the low pass filter 12. Receiving, amplifying and outputting the frequency synthesized means (Freque) The ncy synthesizer 15 receives the 10 MHz signal of the first power dividing means 19 and generates a 795-1295 MHz signal of 1 MHz step according to an external frequency control command, and generates a second mixing means (Mixer). ) 14 mixes the signals from the first amplifying means 13 and the frequency synthesizing means 15, and the band pass filtering means (BPF) 16 is connected to the second mixing means 14. The second amplification means (AMP) 17 amplifies and outputs a 10 MHz output of the band pass filtering means 16, and passes through the phase detector. (18) compares the phase of the 10 MHz reference frequency signal input from the first power divider means 19 and the 10 MHz output signal input from the second amplification means 17 and detects the difference. The loop filter 20 is a phase input from the phase detection means 18. The high frequency component of the signal corresponding to the signal is removed and integrated and supplied to the voltage controlled oscillation means 9, and the second power divider 2Way Divider 21 controls the voltage through the coupling means 10. The output of the oscillation means 9 is divided into two directions and supplied to the up-converter and the down-converter, and the first power divider 19 is the reference frequency refiner ( Ku-band frequency synthesizer characterized in that the 10MHz reference frequency signal of 4) is divided into two directions and supplied to the frequency synthesizing means (15) and the phase detecting means (18). ※ Note: The disclosure is based on the initial application.