Samuel Hopfer

US Patent:

44384157, Mar 20, 1984

Filed:

Jan 29, 1982

Appl. No.:

6/343737

Inventors:

Samuel Hopfer - Brooklyn NY

Assignee:

General Microwave Corporation - Farmingdale NY

International Classification:

H01P 122

US Classification:

333 81A

Abstract:

A digitally programmable attenuator for high speed and a large dynamic range is constructed with a phase-controlled attenuator for small steps of attenuation and an attenuator of switched resistive pads for larger steps. The attenuators are connected in tandem and actuated combinatorially with the phase-controlled attenuator being switched into operation for the small steps, and the resistive pads being switched into operation for the large steps. A phase-controlled attenuator is constructed to permit adjustment of the attenuator characteristic, and a switched-pad attenuator is constructed to be phase shiftless.

US Patent:

42075181, Jun 10, 1980

Filed:

Mar 6, 1978

Appl. No.:

5/883632

Inventors:

Samuel Hopfer - Brooklyn NY

Assignee:

General Microwave Corporation - Farmingdale NY

International Classification:

G01R 2110
G01R 1922

US Classification:

324 95

Abstract:

A radiation detector for free space microwave radiation uses thin film resistive strips, having an equivalent surface resistivity that is large compared to the characteristic impedance of free space, and diode circuits in series with the strips for deriving signals monitoring the radiation intensity over a broad frequency range. The diode circuits are constructed to operate with a uniform response over that frequency range.

US Patent:

42887615, Sep 8, 1981

Filed:

Sep 18, 1979

Appl. No.:

6/076767

Inventors:

Samuel Hopfer - Brooklyn NY

Assignee:

General Microwave Corporation - Farmingdale NY

International Classification:

H01P 518

US Classification:

333116

Abstract:

A microstrip hybrid coupler uses a ground plane having different surfaces, one that is close and coupled to the terminal portions of the microstrip and the others further from and coupled to the coupled microstrip portions. Two shields extend over the coupled microstrip portions; an intermediate shield between the remote ground plane surface and the coupled microstrip portions and an outer shield. The coupled microstrip portions extend over the terminal surface of the ground plane.

US Patent:

40094561, Feb 22, 1977

Filed:

Jan 15, 1973

Appl. No.:

5/323856

Inventors:

Samuel Hopfer - Brooklyn NY

Assignee:

General Microwave Corporation - Farmingdale NY

International Classification:

H01P 122

US Classification:

333 81A

Abstract:

A broadband microwave attenuator is formed by connecting a plurality of PIN diodes in a modified Tee network. Four semiconductor chips of PIN diode material are arranged in a flat layer sandwiched between conductors to form a strip-line configuration of a TEM transmission line, whereby the diodes are part of the line. This strip-line construction is used with outer diodes connected in series circuit relation between input and output terminals, and inner diodes in shunt relation to ground to form the Tee network. The diodes are constructed as silicon chips and are mounted in very close relation with a substantially uniform conductive strip forming the series-circuit connection between the central diodes.

US Patent:

43921086, Jul 5, 1983

Filed:

Apr 24, 1980

Appl. No.:

6/143365

Inventors:

Samuel Hopfer - Brooklyn NY

Assignee:

General Microwave Corporation - Farmingdale NY

International Classification:

G01R 2110
G01R 1922

US Classification:

324 95

Abstract:

A radiation detector for free space microwave radiation uses thin film resistive strips, having an equivalent surface resistivity that is large compared to the characteristic impedance of free space, and diode circuits in series with the strips for deriving d-c signals monitoring the radiation intensity over a broad frequency range. In part of that range, the strips operate like a short dipole antenna. The diode circuits are constructed to operate with a uniform response over the entire frequency range.

US Patent:

42887631, Sep 8, 1981

Filed:

Sep 18, 1979

Appl. No.:

6/076768

Inventors:

Samuel Hopfer - Brooklyn NY

Assignee:

General Microwave Corporation - Farmingdale NY

International Classification:

H01P 118

US Classification:

333164

Abstract:

This invention relates to an analog phase shifter for radio frequency signals that employs a hybrid coupler and biased varactor diodes at its reflection terminals. The diodes are operated so that the normalized reactance is unity (equals the coupler's input impedance) at an intermediate frequency which may be the geometric mean of the end frequencies of a broad bandwidth. The couplers are cascaded in tandem for a 360. degree. phase shift. A balanced configuration of hybrid couplers is used for the phase shifter.

US Patent:

39315738, Jan 6, 1976

Filed:

May 5, 1972

Appl. No.:

5/250582

Inventors:

Samuel Hopfer - Brooklyn NY

Assignee:

General Microwave Corporation - Farmingdale NY

International Classification:

G01R 526
G01R 2104

US Classification:

324106

Abstract:

A detection device for electromagnetic radiation uses strips of thin resistive films connected in electrically conductive paths with the area of spacing between adjacent ones of the strips being greater than the area of the strips to achieve an impedance which is largely resistive over a broad band of radio frequencies. The strips are mounted in dielectric material and exposed to free space radiation. A radiation hazard meter is produced with thermally sinked thermocouple elements forming the resistive strips.