![]() ![]() ![]() ![]() ![]() |
![]() ![]() ![]() |
![]() ![]() |
![]() |
( 22 of 22 ) |
United States Patent | 4,710,970 |
Wu , et al. | December 1, 1987 |
A UHF transmission frequency oscillator generates a UHF radio signal that is frequency modulated by a program signal. The voltage applied to a control voltage input of the UHF transmission frequency oscillator controls the transmission frequency. A sample of the UHF transmission frequency signal is heterodyned with the output of a crystal controlled reference frequency oscillator to generate a frequency difference signal. A voltage controlled VHF radio signal generator produces a VHF signal frequency modulated by the program signal. A phase detector receives the frequency difference signal and the VHF signal frequency modulated by the program signal and therefrom applies a voltage to the control voltage input of the UHF transmission frequency oscillator for the transmission of a UHF radio frequency signal frequency modulated by the program signal. The VHF voltage controlled generator has VHF programmable frequency dividers, which are pre-settable, to establish the VHF radio transmission frequency. The output of the VHF voltage controlled generator is phase locked through the phase detector with the crystal controlled reference oscillator for the stabilizing of the output transmission frequency of the UHF transmission frequency oscillator.
Inventors: | Wu; Joseph C. (Saratoga, CA), Law; Yee-Shing (Milpitas, CA), James; John (Los Gatos, CA) |
Assignee: |
TFT, Inc.
(Santa Clara,
CA)
|
Appl. No.: | 06/774,989 |
Filed: | September 11, 1985 |
Current U.S. Class: | 455/113 ; 331/23; 332/127; 455/119 |
Current International Class: | H03C 3/09 (20060101); H03C 3/00 (20060101); H04B 001/04 () |
Field of Search: | 455/42,110,112,113,119,126 332/18,19 331/18,23,25 |
3644831 | February 1972 | Latker et al. |
4060773 | November 1977 | Hata et al. |
4123725 | October 1978 | Davis |
4186356 | January 1980 | Remy |
4449250 | May 1984 | Kurby |
4610030 | September 1986 | Dominguez et al. |
![]() ![]() |
![]() ![]() ![]() |