| Patent Number |
Title Of Patent |
Date Issued |
| 4481490 |
Modulator utilizing high and low frequency carriers |
November 6, 1984 |
| To minimize carrier leak in the modulation of voice frequencies to the desired line frequency for a carrier system, a first balanced modulator is operated at a low frequency where low carrier-leak modulators may be constructed and a second balanced modulator, directly coupled to the |
| 4447903 |
Forward error correction using coding and redundant transmission |
May 8, 1984 |
| A forward error correcting digital transmission system having two separate transmission channels carrying redundant information. The signal on the first channel is encoded by combining each present bit with itself delayed m bits in time. The signal on the second channel may be encoded in |
| 4405897 |
Frequency deviation testing and adjusting system for frequency modulated oscillators |
September 20, 1983 |
| Deviation of a frequency modulated oscillator (FMO) is set by applying a square wave test signal to the input of the oscillator so as to generate a predetermined amount of symmetrical periodic frequency shift above and below the rest frequency, i.e., the carrier frequency of the FMO, for |
| 4399409 |
Apparatus for testing the linearity of a frequency modulated oscillator |
August 16, 1983 |
| A linearity test signal generator alternately provides a burst of a modulation frequency and no modulation to the modulation input of the frequency modulator oscillator (FMO) under test. A programmable divider is connected to the output of said frequency modulated oscillator to produce |
| 4399408 |
Apparatus for testing the linearity of a frequency modulated oscillator |
August 16, 1983 |
| An APC (automatic phase control) circuit is utilized to measure the linearity of an FMO (frequency modulated oscillator). In accordance with a common APC concept a programmable divider is connected to an output of said frequency modulatable oscillator to produce a binary output signal |
| 4398159 |
Switch mode - class B power amplifier |
August 9, 1983 |
| An input signal is applied to the inverting input of a class B amplifier and to the input of a limiter circuit. The square wave signal from the limiter is applied to the input of a switching amplifier which drives this amplifier between V and ground at the switching rate established by t |
| 4375698 |
Apparatus for testing microwave radios having 35 MHz if using test equipment designed for 70 MHz |
March 1, 1983 |
| A 70.+-..DELTA.f MHz sinusoidal test signal from a standard radio link test set is down converted and shaped to obtain a 35.+-..DELTA.f/2 MHz sinusoidal test signal to be applied to the radio set under test. The output of the radio set is applied to an up converter in which a multipl |
| 4375621 |
Circuit for linearizing frequency modulated oscillators on microstrip |
March 1, 1983 |
| In a microstrip frequency modulated oscillator, the linearity of the modulating circuit incorporating a varactor diode is adjusted by using a microstrip transmission line as a secondary resonator in conjuction with a variable reactor. The varactor is connected to one end of this resonato |
| 4365346 |
Built-in linearity testing arrangement for an FM radio system |
December 21, 1982 |
| The baseband input to a frequency modulation radio transmitter is switchably connectable to a square wave generator, the amplitude of the square wave output being adjusted to provide a predetermined deviation of the FM radio transmitter. The output frequency of a pilot oscillator is |
| 4363131 |
Built-in group delay testing arrangement for an FM radio system |
December 7, 1982 |
| The baseband input to a frequency modulation transmitter is switchably connectable to a square wave generator, the amplitude of the square wave output being adjusted to provide a predetermined deviation of the FM radio transmitter. The output frequency of a pilot oscillator is also appli |
