Claims
- 1. A monolithically integrated active MESFET exhibiting an accurate small signal transfer, adjustable in selected discrete steps, comprising
- A. an input terminal for application of an input signal,
- B. an output terminal for derivation of an output signal and application of drain potentials,
- C. a source terminal for application of source potentials,
- D. an (m+n) fold plurality of terminals for application of transconductance control potentials,
- E. a dual gate MESFET, subdivided into a first n-fold quantity of selectively activated MESFET segments, each segment having a predetermined width to achieve a desired transconductance for relatively larger steps in signal transfer and including
- (1) an electroded source region connected to said source terminal,
- (2) an electroded drain region connected to said output terminal, and
- (3) a gate region defined between said source and drain regions having
- (i) a signal gate electrode disposed between said source and an activating gate electrode electrically connected to said input terminal for modifying the output signal current of said MESFET as a function of the transconductance of the segment, and
- (ii) an activating gate electrode disposed between said signal gate and said drain for turning current flow "ON" and "OFF" in said MESFET segment, and electrically connected to one of said (m+n) fold plurality of transconductance control terminals,
- F. said dual gate MESFET being further subdivided into a second, m-fold quantity of selectively activated MESFET segments, each segment having a predetermined width to achieve a desired transconductance for relatively smaller steps in signal transfer, and including
- (1) an electroded source region connected to said source terminal,
- (2) an electroded drain region connected to said output terminal, and
- (3) a gate region defined beween said source and drain regions having
- (i) a signal gate electrode, disposed between said source and an activating gate electrode, for modifying the output signal current of said MESFET as a function of the transconductance of the segment, and
- (ii) an activating gate electrode disposed between said signal gate and said drain for turning current flow "ON" and "OFF" in said MESFET segment, and electrically connected to one of said (m+n) fold plurality transconductance control terminals, and G. voltage division means electrically connected between said input terminal and said m-fold signal gate electrodes to apply a reduced signal voltage thereto so that wider segments may be used while a proportionately smaller equivalent transconductance is provided,
- said (m+n) fold MESFET segment transconductances being weighted and ordered for converting to an electrical control signal coupled to said (m+n) fold control terminals such that successive combinations of active segments provide a desired series of transfer values.
- 2. The monolithically integrated MESFET set forth in claim 1 wherein
- said voltage division means is a pair of resistances formed on said substrate by a photolithographic process.
Government Interests
The Government has rights in this invention pursuant to Contract No. F19628-80-C0002, awarded by the U.S. Air Force.
US Referenced Citations (5)