Ricky H Chen, 59PO Box 3996, Cedar Park, TX 78630

6040731, Mar 21, 2000

May 1, 1997

8/848930

Ricky Y. Chen - Irvine CA
Lloyd F. Linder - Agoura Hills CA
Don C. Devendorf - Carlsbad CA
Matthew S. Gorder - Riverside CA

Raytheon Company - El Segundo CA

G06F 744
H03L 500

327359

A "gain control differential pair" (GCDP) conducts current in response to a differential drive signal, with the gain of a signal path formed via the current circuit of one of its transistors controlled by the drive signal. The GCDP is preferably driven with a drive circuit that receives a symmetrical input signal and produces an offset differential drive signal which has the effect of keeping one of the GCDP's transistors turned off over a wider portion of a symmetrical input signal's voltage range, thereby reducing GCDP-caused noise. One or more GCDPs are implemented as part of a Gilbert mixer to regulate the amount of RF current that flows between the mixer's output and input stages, which eliminates the need to provide gain control in other circuits fed by the mixer. When driven with an offset drive signal, the Gilbert mixer simultaneously provides gain control, low distortion, low power consumption and excellent LO/RF isolation.

6118811, Sep 12, 2000

Jul 31, 1997

8/903807

Robert T. Narumi - Dove Canyon CA
Lloyd F. Linder - Agoura Hills CA
Erick M. Hirata - Torrance CA
Don C. Devendorf - Carlsbad CA
Matthew S. Gorder - Riverside CA
Phung N. Phan - Simi Valley CA
Ricky Y. Chen - Irvine CA

Raytheon Company - Lexington MA

H04B 138

375219

A transceiver has a digital signal processor which can insert calibration signals of known level and frequency into transmitters for calibration and correction of transmitter parameters. An output of the calibrated and corrected transmitter is subsequently coupled into a calibration mixer along with a mixing signal (e. g. , from a local oscillator generator. The outputs of the calibration mixer have known levels and frequencies and are inserted into receivers for calibration and correction of receiver parameters.

5859558, Jan 12, 1999

Apr 11, 1997

8/827855

Ricky Y. Chen - Irvine CA
Lloyd F. Linder - Agoura Hills CA
Don C. Devendorf - Carlsbad CA

Raytheon Company - El Segundo CA

G06G 712

327355

A low voltage analog front end (AFE) includes a differential transistor pair which converts an input voltage, typically A. C. -coupled to the pair's control inputs, to a differential current. Impedance networks connected to each transistor's control input are joined together at a common node, and a current source is connected to the node which causes DC bias currents to be mirrored through the pair's current circuits, so that the AFE's differential output current comprises a differential current produced by the pair in response to an input voltage and superimposed on the DC bias currents. The current source preferably generates mirrored currents which are larger than its reference current to linearize the pair's response and to provide the AFE with a wide dynamic range. An input to the AFE sees a low impedance which is about equal to the sum of the impedance networks, which can be resistive or complex as needed. The AFE has widespread application as a front end circuit, serving as a low voltage input stage for a Gilbert mixer, for example.