Dale R Zimmerman

48127809, Mar 14, 1989

Mar 10, 1988

7/166142

Dale E. Zimmerman - Dallas TX

Texas Instruments Incorporated - Dallas TX

H03F 345

330253

A differential amplifier (230) with input differential dual gate FETs (232,234) with one pair of gates (235,237) tied together, with sources tied together, and with a current source (236,238) for each of the FETs and inputs at the current source terminals is disclosed. These amplifiers provide large CMRR at frequencies to a few GHz, and fabrication in gallium arsenide is disclosed. A push-pull single-ended output stage provides good power handling and VSWR.

53212843, Jun 14, 1994

Dec 18, 1989

7/453244

Bentley N. Scott - Richardson TX
Dale E. Zimmerman - Dallas TX

Texas Instruments Incorporated - Dallas TX

H01L 2980

257282

A GaAs field effect transistor with a source contact including both an ohmic contact and a Schottky barrier, the Schottky barrier between the ohmic contact and the gate, is disclosed. The Schottky barrier provides a high frequency source contact close to the active channel and thereby reduces the parasitic source resistance at microwave and higher frequencies.

47527501, Jun 21, 1988

May 30, 1986

6/869145

Dale E. Zimmerman - Dallas TX
Carl M. Panasik - Garland TX

Texas Instruments Incorporated - Dallas TX

H03H 964
H03H 1500

333166

A hybrid programmable transversal filter (HPTF) is described that employs a LiNbO. sub. 3 SAW delay line and two monolithic dual-gate GaAs FET arrays to control magnitude and sign of the 16 tap weights. The HPTF is completely programmable and is constrained only by the bandwidth (100 MHz centered at 250 MHz) and the number of taps. Theoretical calculations of tap weight control range and dynamic range are presented, compared with experiment and used to justify the hybrid LiNbO. sub. 3 SAW - GaAs FET combination. Dynamic range of 85 dB and a continuously variable tap weight control range of 70 dB are demonstrated.

53878876, Feb 7, 1995

Mar 4, 1994

8/205751

Dale E. Zimmerman - Dallas TX
James W. Culver - Richardson TX
Carl M. Panasik - Garland TX

Texas Instruments Incorporated - Dallas TX

H03H 738
H03H 900
H03H 9205

333166

A digitally controlled programmable transversal filter (DCPTF) employing a lithium niobate surface acoustic wave (SAW) delay line and two large scale integration (LSI) gallium arsenide integrated circuits to digitally control the magnitude and sign of the 32 tap weights from the delay line. The DCPTF results in a significant reduction in size over the prior art with little sacrifice in performance. The DCPTF is completely programmable and is constrained only by the bandwidth and the number of taps.