Itt Corporation

Itt Gilfillan, a Division of Itt Corporation

International Telephone and Telegraph Corporation

Itt Gilfillan

William G Sterns

Ronald I Wolfson

Ching-Fai Cho

John D Foglesonger

Gregory G Charlton

Ching F Cho

Robert E Johnson

Victor M Petrillo

A high gain antenna that produces a pencil beam along the ground and a lower gain antenna that produces a beam extending above the pencil beam are coupled to a source of r.f. pulses so that the amplitude of the r.f. pulses applied to the high gain antenna is less than the amplitude of the r.f. pulses applied to the lower gain antenna during airplane detection and the full amplitude of the r.f. pulses during a pulse segment is applied to the high gain antenna during wind pattern detection.

ASR system for microburst detection

A modified branch line coupler amplitude equalizer circuit employing cross arms and branch lines of varying lengths and impedances to minimize the return loss of the circuit.

Microwave amplitude equalizer circuit

A two port dual bandpass microwave filter consisting of 'n' resonant cavities. Each cavity resonates in two independent modes at displaced frequencies so that the filter has two passbands in a desired frequency band. By orienting an incoming waveguide at an angle with respect to the filter, both TE and TM modes can be excited to produce two separate passbands. The passbands may have either equal or unequal characteristics. Fine tuning of the TE and TM modes is accomplished using tuning plungers or tuning screws. The dual bandpass response of the new filter is achieved by utilizing the TE.sub.1,1,1 and TM.sub.0,1,0 modes in right circular cylindrical cavities, or equivalent modes in rectangular, or other cavities. These modes are orthogonal so they do not couple to each other. The cavity loaded Qs are independently adjustable, so the two passbands can have the same or different bandwidths, the same or different amplitude ripples and the same or different phase responses. The dual bandpass microwave filter provides filtering with but one set of cavity resonators rather than two. It does not require three port microwave junctions with critical path lengths. The filter is well-suited to filter the output of a single transmitter capable of operation at two differential frequencies.

Dual bandpass microwave filter

The present invention constitutes a microwave circuit structure such as a phase shifter which has a dielectric cylindrical support structure with a ground plane on the inside and a microwave circuit mounted on the outside. A cylindrical shield is mounted coaxially around the circuit, spaced therefrom by a second dielectric. Two embodiments are shown in microstrip and stripline.

Tubular microwave phase shifter

The variable directional coupler of the subject invention employs 3, 4 or n branches in TEM transmission media, such as coax, stripline and microstrip. Precise control of the coupling is acheived by a variable susceptance connected near the mid-point of the crossover.

Variable directional coupler

An antenna feed network implemented preferably in stripline for connecting the elements of a linear or planar array with a common port for transmit/receive operation. The network acts as a power divider/combiner and is entirely reciprocal. The network is realized in the form of a pattern of conductive traces on a single dielectric sheet of the stripline arrangement between parallel, spaced ground planes and does not require interconnections among multiple planes. The network may be utilized as a single or multiple beam forming network with the path lengths to the respective array radiators patterned to achieve a frequency scanning or beam normal array design.

Antenna feed network employing over-coupled branch line couplers

An improved serpentine feed and method of making same. The invention includes a block of conductive material having a primary microwave waveguide channel and at least one secondary channel. Each secondary channel has at least one broadwall common to the primary channel. A high performance coupler is provided in the common broadwall by which microwave energy communicates from the primary channel to the secondary channel. The claimed method of the invention includes the steps of (a) machining mating halves of a first elongated channel into first and second blocks of conductive material; then, (b) machining mating halves of a plurality of second channels into the first and second blocks longitudinally parallel with at least a portion of the halves of the first channel thereby providing a plurality of common broadwalls between the first channel and each of the second channels; next, (c) machining a plurality of slots in each of the common broadwalls between selective first and second channels; and finally, (d) either mechanically fastening or bonding the first and second blocks in alignment such that halves of the first and second channels mate to provide primary and secondary microwave waveguides respectively.

Serpentine feeds and method of making same

An antenna element including a microstrip radiating element having a microstrip feed line and a ground plane on opposite sides of a substrate, with at least one of a plurality as resonators on the same side of the substrate as the microstrip feed line, and a dipole radiator having an increased bandwidth and insulated from the feed line and from the plurality of resonators.

Antenna elements and arrays

This invention relates to two embodiments of microwave polarization control networks. The first produces two sets of orthogonal linear polarizations and constitutes a two position transfer switch and a directional coupler having two ports alternating as input and isolated ports and two ports alternating as through and coupled output ports. The transfer switch is connected to switch an input to one or the other of the two ports alternating as input and isolated ports and couple the other to a termination. An ortho-mode transducer junction, having two input ports, has one input port coupled directly to one of the output ports of the directional coupler and the other input port connected in series through a 0.degree./180.degree. phase shifter to the other output port of the directional coupler. A dual mode waveguide is employed for transmitting a variable polarization output from the ortho-mode junction. In another embodiment, the transfer switch is not employed, and a 90.degree. differential phase shifter is incorporated in the dual mode waveguide whereby either linear or circular polarization may be obtained.

Microwave polarization control network

An antenna element including microstrip having a microstrip feed line and ground plane on opposite sides of a substrate, a resonator on the same side of the substrate as the microstrip feed line, and a dipole insulated from the feed line and from the resonator.

Microstrip antenna with resonator feed

A broadband TEM mode four-port hybrid in a single-level microwave circuit in a transmission line medium selected from among the stripline, microstrip, airstrip, etc. media. The device employs coupled strip all-pass filter elements to provide a hybrid wherein isolation to the cross ports, power division to the coupled ports, and the 0.degree. and 180.degree. output phase relationships are independent of frequency over substantial frequency bandwidths.

Broadband four-port TEM mode 180.degree. printed circuit microwave hybrid

A TEM mode balun in a single-level microwave circuit in a transmission line medium selected from among the stripline, microstrip, airstrip, etc. media. The device employs coupled-strip all-pass filter elements to provide a pair of balanced input/output lines in 180.degree. phase relationship and an unbalanced line port.

Growing community of inventors

Canoga Park, CA, United States of America

William G Sterns