Trw Limited

Duncan M Smith

Barry Ross Allen

Kevin Wesley Kobayashi

Aaron K Oki

John E Dowsing, Iii

Arvind K Sharma

Jeffrey M Edwards

A quenchable VCO that is adapted to be used in switched band synthesizer applications. The VCO may be formed from a heterojunction bipolar transistor (HBT) in a common collector configuration. A quenching circuit which includes a p-i-n diode, is electrically coupled in series with the collector of the HBT. The p-i-n diode is adapted to be monolithically integrated with the HBT. Since the p-i-n diode is electrically connected to the collector of the HBT, as opposed to the base and emitter terminals of the HBT, which forms the main oscillator feedback loop, the Q-factor of the p-i-n diode will have relatively less loading on the phase noise of the HBT oscillator. Moreover, since the p-i-n diode is isolated from the base-emitter junction, the configuration will result in reduced frequency pulling and generation of spurious oscillation and transient effects due to the switching of the p-i-n diode quenched circuit. The use of a p-i-n diode for quenching of VCO also provides other inherent advantages over other types of semi-conductor switches, such as FET, Schottky diodes, PN diodes for quenchable VCO applications because p-i-n diodes are relative insensitive to RF and noise modulation. Because the p-i-n diode can be constructed from existing HBT collector-base MBE epitaxy layers, the quenching circuit can be manufactured relatively inexpensively.

Quenchable VCO for switched band synthesizer applications

A small elliptic high pass filter is incorporated into a low noise block downconverter (LNB) to reject image frequencies in a 12 GHz Direct home satellite television Broadcasting System (DBS). A waveguide transition with separate electric probes receives Ku-band satellite signals and transmits the signals to low noise amplifiers (LNAs), a power combiner, an elliptic high pass filter, and a HEMT MMIC receiver. Within the HEMT MMIC receiver, the signal is passed through an RF amplifier stage. A mixer mixes the signal from the RF amplifier stage with a local oscillator signal to produce an intermediate frequency (IF). An IF amplifier stage amplifies the IF signal which is further processed by a television decoder box. Due to the unique response of the elliptic high pass filter, the elliptic high pass filter provides a superior image rejection with lower insertion loss for the LNB, and therefore provides improved television reception quality.

Low noise block downconverter

An enclosure assembly for a high frequency integrated circuit. The enclosure assembly includes a plurality of lead terminals that are part of a lead frame. The lead terminals are connected to electrical ports of the circuit within the enclosure to connect the circuit to other integrated circuits and/or to a printed circuit board. A portion of the lead terminals outside of the enclosure has a specially shaped flared region that establishes the characteristic impedance of the circuit on the lead lines outside of the enclosure.

High frequency microelectronic circuit enclosure

The present invention resides in a push-push voltage controlled oscillator (VCO) utilizing parallel LC resonant tank circuits for improved phase noise characteristics. The push-push VCO of the present invention includes two voltage controlled oscillators connected in parallel and in phase opposition, with each oscillator including a transistor connected in series with the parallel LC resonant tank circuit. The oscillators operate at the same resonant frequency f.sub.0, but are 180 degrees out of phase. Therefore, the fundamental and odd harmonics of the resonant frequency f.sub.0 cancel each other out and the even harmonics add together to produce an output signal at twice the resonant frequency f.sub.0.

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Torrance, CA, United States of America

Duncan M Smith