31
Hallford Ben R: Rf rejection filter. Collins Radio Company, July 18, 1972: US3678433 (17 worldwide citation)

An RF suppression filter using several quarter RF wavelength long strips in parallel that are open-ended to form an RF ground at their common tie-points in the form of a section of conductive line. This base line is extended to terminations at each end to a length beyond the respective outside stubs ...


32
Frazier Melvin A: Voltage standing wave ratio detecting and adjusting apparatus. Collins Radio Company, Lutz Bruce C, October 15, 1974: US3842358 (17 worldwide citation)

Hysteresis type detection apparatus for detecting the voltage standing wave ratio (VSWR) of a transmitting system. When the detection apparatus determines that the VSWR exceeds a predetermined value, it actuates a servo-system which adjusts impedances in a coupling unit between the transmitter and t ...


33
Hallford Ben R: Microwave balanced mixer circuit. Collins Radio Company, April 25, 1972: US3659206 (17 worldwide citation)

A balanced microwave mixer for converting a microwave input signal to an intermediate frequency output using a microwave carrier as a local oscillator signal with the two microwave signals combined and divided out through two signal carrier lines via a hybrid 'rat race' circuit ring. The two signal ...


34
Stump Theodore M, Williford Jerry G: Frequency shift keyed demodulator. Collins Radio Company, February 26, 1974: US3794928 (17 worldwide citation)

A frequency shift keyed (FSK) modem (modulator and/or demodulator) utilizing a phase lock loop which modem may operate at any of several predetermined frequencies and whose output for the modulator section, is combined with a frequency shift keyed signal and the result passed through a low pass filt ...


35
Melvin William J: Digitalized multiplier. Collins Radio Company, November 2, 1971: US3617723 (17 worldwide citation)

A binary number in sign-magnitude format is multiplied by a second binary number in two's complemented format. The second number is stretched by repeating its sign bit a number of times equal to the number of magnitude bits of the first number, and the second number is then two's complemented when s ...


36
Sharma Roshan La: Algorithm for synthesizing economical data communication network. Collins Radio Company, November 14, 1972: US3703006 (17 worldwide citation)

A technique for optimizing the connections of a plurality of stations to a central point wherein a connection link has a predetermined maximum line weight and where optimum is defined as a distance related cost comprising setting up a trial configuration in a computer and interchanging stations on a ...


37
Tanaka Edward H, Riach James C: Carrier squelch scheme. Collins Radio Company of Canada, March 9, 1971: US3569840 (16 worldwide citation)

A carrier squelch system monitoring both an AGC voltage developed in a superheterodyne receiver and the signal level present in the receiver as represented by the IF carrier signal, with inverse variation of the gain of an AC amplifier in the squelch circuit under control of the AGC voltage, develop ...


38
Van Englehoven Clarence A, Richter David L: Frequency controlled flux detector excitation. Collins Radio Company, December 7, 1971: US3626280 (16 worldwide citation)

A flux detector saturation control circuit senses core saturation time for monitoring rate of change of current through the core drive winding. A frequency control loop for the core driving source is responsive to saturation detection to maintain a time symmetry between a driving source synchronizin ...


39
Andrea John J, Dennison Charles M: Fractional frequency divider. Collins Radio Company, March 23, 1971: US3571728 (16 worldwide citation)

A fractional frequency divider circuit comprising a pair of frequency dividers arranged in parallel and each of which divides the input signal frequency F.sub.s by an odd integer N to produce a two level output signal with an unbalanced ratio of upper to lower level time intervals. Synchronizing mea ...


40
Beaver William D: Monolithic multifrequency resonator. Collins Radio Company, March 9, 1971: US3569750 (15 worldwide citation)

A multifrequency resonating device comprising a single, piezoelectric quartz crystal plate having a plurality of different thickness plateaus formed thereon and separated, one from the other, by sections of beveled surface areas which create acoustic impedance mismatches between the plateaus. Each p ...