Telecommunications – Transmitter – Angle modulation
Patent
1989-08-14
1991-06-25
Eisenzopf, Reinhard J.
Telecommunications
Transmitter
Angle modulation
455119, 455264, 332127, H04B 104
Patent
active
050274295
ABSTRACT:
A frequency modulator utilizing a frequency synthesizer is disclosed. The modulator is especially useful in a mobile radio communication apparatus. The synthesizer includes a phase locked loop made up of a voltage controlled oscillator (VCO), a programmable frequency divider, a phase comparator, a second frequency divider, a reference oscillator, and a low-pass filter. When a channel control signal is input to the programmable frequency divider, the modulator sensitivity of the voltage controlled oscillator is undesirably deviated according to the channel selection. An increase of the modulator sensitivity due to an increase of the oscillation frequency is compensated for by adding a simple FET to the VCO bias circuit. A control voltage from the phase locked loop is applied to both the voltage controlled oscillator and its bias circuit. The modulator can compensate for changes in sensitivity over a wider frequency bandwidth without expanding the circuit elements of the bias circuit therefore making the modulator especially useful for portable use.
REFERENCES:
patent: 2298409 (1942-10-01), Peterson
patent: 2640193 (1953-05-01), Carter et al.
patent: 4117422 (1978-09-01), Hunt
patent: 4348770 (1982-09-01), Ito
patent: 4477781 (1984-10-01), Ruess, Jr.
patent: 4501019 (1985-02-01), Matsukura
patent: 4503402 (1985-03-01), Englund, Jr.
patent: 4618831 (1986-10-01), Egami et al.
patent: 4660002 (1987-04-01), Iijima et al.
patent: 4721927 (1988-01-01), Aota et al.
Comsat Techanical Review, A. Standing, vol. 5, No. 2, Fall 1975, pp. 355-366.
Charonel Lisa
Eisenzopf Reinhard J.
NEC Corporation
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