US3833858A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High gain solid-state distributed interaction microwave amplifier
Assignee: University of Utah
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Filing: 1973-06-15
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Granted: 1974-09-03
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Expires: 1993-06-15
Abstract
Abstract Traveling-wave amplification of microwave energy having frequencies up to 500 GHz is provided by a semiconductor (GaAs, GaP, InAs, InP) which has a thin epitaxial layer capable of exhibiting the property of negative differential conductivity. A thin resistive layer is applied on the skin of the epitaxial layer to smooth out the dc electric field profile and allow use of longer layers with a selective control of band pass and gain properties of the amplifier.
Inventors
- 👤 O Gandhi
- 👤 L Metz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:33
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/54; H03F3/55
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
55 words
The device of claim 1 further comprising ohmic strips on the resistive layer outside the space between the transducers, and terminals connected to said ohmic strips for applying a variable dc voltage to produce an electric field up to about 7 KV per centimeter of distance between the ohmic strips to provide electronic gain control.
Claim 2
Dependent Claim
22 words
The device of claim 2 wherein the resistive layer has a sheet resistance less than the negative resistance of the epitaxial layer.
Claim 3
Dependent Claim
35 words
The device of claim 3 further having a layer of high permittivity material having a thickness of about 50 microns and extending over the surface of the resistive layer between the input and output transducers.
Claim 4
Dependent Claim
12 words
The device of claim 4 wherein the semiconductor material is gallium arsenide.
Claim 5
Dependent Claim
37 words
The device of claim 1 further having a layer of high dielectric material having a thickness of at least about 50 microns and extending over the surface of the resistive layer between the input and output transducers.
Claim 6
Dependent Claim
25 words
The device of claim 1 wherein the semiconductor material is selected from the group consisting of gallium arsenide, gallium phosphide, indium arsenide and indium phosphide.
Claim 7
Independent Claim
125 words
A method for amplifying a band of electromagnetic waves comprising: providing a substrate of semiconductor material; forming an epitaxial layer having a thickness of at least three microns that is capable of exhibiting the property of negative differential conductivity; forming a resistive layer on the side of the epitaxial film layer opposite the substrate to suppress low frequency instability of the device; applying input and output terminals including input and output transducers on the surface containing the epitaxial layer with the transducers being spaced apart in the direction of wave propagation; applying ohmic terminals outside of the space between the transducers; feeding electromagnetic waves having a frequency up to about 500 GHz to the input terminal; and applying a dc voltage between said ohmic terminals.
Claim 8
Dependent Claim
37 words
The method of claim 8 wherein the resistive layer is formed by modifying the surface of the epitaxial layer to form a resistive layer having a sheet resistance less than the negative resistance of the epitaxial layer.
Claim 9
Dependent Claim
18 words
The method of claim 8 wherein said resistive layer is formed by ion implantation of the epitaxial layer.
Claim 10
Dependent Claim
26 words
The method of claim 8 wherein the gain of the amplifier is controlled by varying the magnitude of the dc voltage applied between said ohmic terminals.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |