US 6,072,992 AGranted

High-frequency device

AssigneeMatsushita Electric Industrial Co., Ltd.

InventorsAkira Mishima, Shigeharu Sumi, Motoyoshi Kitagawa

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Abstract

A high frequency apparatus for receiving digital modulated high frequency signal which withstands vibration and is easy to adjust for tuning, yet presents clear oscillation signal. The invented apparatus has an input terminal(101), a mixer(104) which receives at one input the signals supplied to input terminal(101) and at the other input an output signal of local oscillator(103), and output terminals(107,108) to which the output signal of mixer(104) is delivered. A voltage controlled oscillator constituting said local oscillator(103) has an oscillating section and a tuning section; the tuning section has a movable conductive member(119) and a gluing agent(120) for maintaining a state after adjustment. Control loop has a high loop band width which is large enough so as the noise of local oscillator(103) is not dominated by noise of the above mentioned voltage controlled oscillator.

Claims111

Dependent claims

A high frequency apparatus comprising an input terminal for inputting digital modulated high frequency signals, a mixer which receives at one input the signals imputted to input terminal and at the other input an output signal of local oscillator, and an output terminal to which the output signal of mixer is delivered;

said local oscillator being comprised of a voltage controlled oscillator, a frequency divider, a phase comparator and loop filter, the last three items disposed intervening in the control loop, said voltage controlled oscillator being comprised of an oscillating section and a tuning section, which tuning section being comprised of a frequency adjusting section and a means for maintaining a state of the frequency adjusting section after adjustment;
wherein said control loop has a loop band width so that the noise of said local oscillator is not dominated by the noise of said voltage controlled oscillator, and
the signal level of the reference frequency signal supplied to said phase comparator is made to be smaller, relative to a comparative signal supplied from the frequency divider to the comparator, in a respective frequency excluding a portion substantially at the center of the frequency.

A high frequency apparatus comprising an input terminal for inputting digital modulated high frequency signals, a mixer which receives at one input the signals inputted to input terminal and at the other input an output signal of local oscillator, and an output terminal to which the output signal of mixer is delivered;

said local oscillator being comprised of a voltage controlled oscillator, a phase comparator and a frequency divider and loop filter, the last three items disposed intervening in the control loop, said voltage controlled oscillator being comprised of an oscillating section and a tuning section, which tuning section being comprised of a frequency adjusting section and a means for maintaining a state of the frequency adjusting section after adjustment;
wherein
said control loop has a loop band width so that the noise of said local oscillator is not dominated by the noise of said voltage controlled oscillator, and signal level of the reference frequency signal supplied to said phase comparator is made to be smaller, relative to comparative signal supplied from frequency divider to comparator, in a respective frequency excluding a portion substantially the centre of frequency.

said local oscillator being comprised of a voltage controlled oscillator, a phase comparator, a frequency divider and a loop filter, the last three items disposed intervening in the control loop, said voltage controlled oscillator being comprised of an oscillating section and a tuning section, which tuning section being comprised of a frequency adjusting section and a means for maintaining a state of the frequency adjusting section after adjustment;
wherein
said control loop has a loop band width so that the noise of said local oscillator is not dominated by the noise of said voltage controlled oscillator, and signal level of the frequency distribution characteristic at the centre frequency of the reference frequency signal supplied to said phase comparator is made to be lower, relative to the signal level of frequency distribution characteristic in the vicinity of centre frequency outputted from said local oscillator to mixer, than a signal level to be noise-reduced by the high loop band width in a same off-set frequency from the respective centre frequency excluding a portion substantially the centre of frequency in the frequency distribution characteristic.

Dependencies are inferred from the claim text.