Abstract: A precision signal delay apparatus and method for introducing time delay to a signal. Precision delay is introduced by a pair of delay locked loops (DLLs) connected in series each with selectable delay (i.e., a Vernier-type circuit). Nonuniformity in the precision delay is compensated with a delay compensation circuit. The apparatus and method may be used for phase shifting, data delay, precision pulse width modulation, and precision time windowing.

Abstract: A planar MESFET transistor includes a plurality of FET elements. Each FET element includes a doped planar channel, and source and drain coupled to the ends of the channel. A gate conductor extends over a portion of the channel at a location lying between the source and drain, a first predetermined distance from the drain. A field plate is connected to the gate conductor, and extends toward the drain a second predetermined distance, isolated from the channel except at its gate conductor connection by a dielectric material.

Abstract: A method for testing a pulse Doppler radar sensor circuit comprising at least one antenna, and a switch circuit, comprising the steps of 1) configuring said switch circuit such that a first path between an input terminal and a first output terminal and a second path between an input terminal and a second output terminal introduce different phase delays to an input signal, 2) providing an input signal to the switch circuit at said input terminal, and 3) comparing a signal at the first output terminal and a signal at the second output terminal to determine if the sensor circuit is functioning.

Abstract: The invention is a method and apparatus for determining the locations of a plurality of actual objects based on the output of a plurality of range sensors. A multiplicity of range measurements are obtained from a plurality of sensors, each sensor capable of providing a multiplicity of range measurements. The range measurements from the plurality of sensors are correlated with each other to generate a list of potential objects and to order that list of potential objects from highest to lowest likelihood of being an actual object. The order may be based upon a cumulative error of the individual sensor measurements upon which the potential object is based. The ordered list of potential objects is then pared down to a smaller list of actual objects by assuming that the potential object highest in the ordered list as an actual object, and then removing from the list all other lower-ordered potential objects that are based on any of the range measurements upon which the selected object is based.

Abstract: A dual channel monopulse transceiver is described for use at millimeter wavelengths and for the detection of targets for vehicle collision avoidance. A microstrip antenna is located on one side of a plate and a transceiver microstrip circuit coupled to the antenna is located on the other side of the plate. The transceiver includes a reflective balanced mixer, an isolated balanced mixer and a hybrid circuit for connecting the mixers to antenna feed points. Sum and difference signal generating circuits are employed to provide single and split antenna beams for the detection of targets.

Abstract: Microwave apparatus for altering the phase-front of microwave energy propagating in a predetermined path and in which there is provided a panel having a plurality of electrically-conductive leads extending substantially parallel to the electric vector of the wave, each of these leads is lengthwise divided into sections. A semiconductor junction is formed in the semiconductor material at each end of each section of lead. Each pair of confronting junctions together with the semiconductor material therebetween provide a surface oriented semiconductor diode switch. A switching voltage is applied to each of the leads so as to render at least some of the diodes in each of the leads simultaneously either conductive or non-conductive, thereby allowing each of the leads to be electrically either divided into said sections or continuous throughout at least a portion of its length.

Abstract: A microwave antenna and receiver assembly is described for use at gigaherz frequencies wherein the antenna is a microstrip antenna and the receiver includes a stripline filter circuit which is integrated in a layered configuration with both the microstrip antenna and the amplifier so as to achieve a very low noise figure, a low SWR and preserve good receiver characteristics, while being easily assembled inside a common radome housing. An inexpensive substrate material formed of alternating layers of polypropylene and woven glass is described for use with the microstrip antenna and other microwave structures.

Abstract: Several embodiments are shown for a quick connect/disconnect microwave coaxial connector which is held together under magnetic force. In one embodiment, the ends of coaxial cables are provided with annular magnets and the end faces ground flat. A good low SWR coaxial connection is made and held by simply pushing the ends together. In another embodiment, ring magnets are employed to hold standard coaxial ends together while enabling their disconnection by pulling them apart. A magnetic adapter is used to facilitate coaxial connections.

Abstract: A mesa-type PIN diode and method for making same are disclosed. A diode made according to the present invention includes a junction formed in the top surface of the mesa-shaped structure, having an area that is less than (and preferrably, approximately half) the area of the top surface. A highly-doped, N-type conducting layer is formed in the side-walls of the mesa-shaped structure. The resulting diode is subject to greatly reduced charge carrier recombination effects and suffers from much less carrier-to-carrier scattering than conventional diodes. Thus, a diode made according to the present invention is capable of achieving much higher stored charge, lower resistance, lower capacitance, better switching characteristics, and lower power consumption than one made according to the prior art. Particular utility is found, inter alia, in the areas of high-frequency microwave and monolithic circuits.

Abstract: An electronic attenuator device is provided whose attenuation characteristics are substantially insensitive to variations in component element parameters and ambient temperature changes. Advantageously, an attenuator device made according to the present invention may be constructed at substantially reduced cost without loss of attenuation precision.

Abstract: A mesa-type PIN diode and method for making same are disclosed. A diode made according to the present invention includes a junction formed in the top surface of the mesa-shaped structure, having an area that is less than (and preferrably, approximately half) the area of the top surface. A highly-doped, N-type conducting layer is formed in the side-walls of the mesa-shaped structure. The resulting diode is subject to greatly reduced charge carrier recombination effects and suffers from much less carrier-to-carrier scattering than conventional diodes. Thus, a diode made according to the present invention is capable of achieving much higher stored charge, lower resistance, lower capacitance, better switching characteristics, and lower power consumption than one made according to the prior art. Particular utility is found, inter alia, in the areas of high-frequency microwave and monolithic circuits.

Abstract: A microwave apparatus for warming of a liquid such as blood or IV fluids in which the warming occurs in-line by means of a microwave heating cavity having a source of microwave energy coupled thereto. A support element in the form of a bobbin forms an assembly with an IV tube wound about the bobbin. This tubing-bobbin assembly is inserted into the microwave heating cavity. A non-invasive, non-perturbing microwave temperature monitor is provided coupled to the microwave heating cavity for monitoring the temperature of liquid flowing in the IV tube. Controls are provided including a desired operating temperature selector for combining signals representative of, not only cavity temperature, but also inlet and outlet temperatures to control the power level of microwave energy delivered to the heating cavity.

Abstract: A semiconductor device and associated method of fabrication in which the device includes a semiconductor substrate having a cavity therein extending in a frame pattern. An insulating layer such as one of silicon nitride is deposited in the cavity followed by the deposition of polysilicon to substantially fill the cavity and provide structural support. An epitaxy layer is formed over the surface of the substrate along with a second insulating layer having windows defined therein for enabling ohmic contact with the epitaxy layer and substrate, resectively. Metallization is deposited to form separate beam leads to provide ohmic contact at the epitaxy layer and substrate.

Abstract: A mobil radio communication network utilizing meteor burst communication medium. A master station communicates with a plurality of mobile radio stations using digital messaging. Each of the master stations generates polling data sent over a plurality of sectors to identify mobile radio stations to which messages are to be transmitted. Messages for transmission are composed at the master station, and when an acknowledgement is received in one of a plurality of receive sectors at the master station from the polling command, the messages are subsequently transmitted. Transmission of a message following receipt of an acknowledgement occurs only over a transmit sector containing the received acknowledgement signal. Messages may be composed in each of the mobile radio stations and sent digitally to the master station which responds by sending an acknowledgement over the transmit sector which is coextensive with the receive sector having processed the acknowledgement signal.

Abstract: A system and associated method that combines microwave detection (radiometry) with microwave heating (hyperthermia) for the treatment of cancer with a microwave radiometric detector is operable during a receive mode of operation to establish signal path characteristics and a microwave transmitter is operable during a transmit mode of operation to carry out the hyperthermia treatment. There is provided an antenna array of a plurality antennae disposed over the tumor site. These antennae are coupled to separate signal channels. During the receive mode of operation the separate channel signals are combined for coupling to the microwave radiometric detector to enable adjustment of the phase of the separate antenna signals so as to maximize the signal detected at the microwave radiometric detector. Thereafter, during the transmit mode of operation the microwave transmitter couples signals to the signal channels to provide beam focusing of the microwave energy on to the tumor site.

Abstract: A method and apparatus for cancerous tumor detection employing a plurality of microwave antennae supported in an array conforming substantially in size to the breast that is being screened. In one embodiment of the invention a single array is used and another embodiment for larger breasts a pair of arrays are used. A microwave radiometer is used for detecting temperature readings corresponding respectively to the breast temperature at sites underlying the receiving antennae. Also, in accordance with the invention compression is employed so as to reduce tissue thickness enabling far more rapid reading of antenna sites.

Abstract: A two-terminal field effect transistor device which is capable of operation as an oscillator including a field effect transistor connected in a two-terminal manner. The transistor has the usual drain source and gate electrodes and oscillating instability is provided by means of an inductance means of value so as to provide this circuit instability to enable circuit oscillations. The two-terminal arrangement is enabled by means of essentially interconnecting the gate and drain electrodes by way of said inductance means.

Abstract: A method of making a microwave semiconductor component and concurrently forming therewith a mounting membrane adapted for positioning the semiconductor component in an RF transmission medium such as a waveguide. Substantially concurrently with the deposition of a metallic film in connection with forming a semiconductor elements, there is deposited a metallic membrane on the base silicon substrate and outside of the circuit element. The outer periphery of the base substrate is removed to expose the membrane. The metallic membrane is preferably of gold.

Abstract: A method of making a multiplicity of microwave integrated circuits is disclosed wherein a thin glass substrate is etched to contain both via holes and large area holes which receive discrete active devices therein. An electrically and thermally conductive carrier is adhered to one surface of the glass substrate with the electrical interconnections and circuit components formed on the opposing surface of the glass substrate. The method enables a multiplicity of microwave circuits to be made and tested by batch processing techniques prior to division into individual circuits.

Abstract: A non-invasive temperature monitoring apparatus used in association with a guided wave member that may be for the purpose of sterilization and that is adapted for microwave heating of a substance that is absorptive at microwave frequencies and that is held in some type of container or connector that is transparent at microwave frequencies. The apparatus comprises a length of waveguide. A coupling aperture is defined in the guided wave member. The length of waveguide is supported with one end thereof about the coupling aperture. A microwave radiometer detection circuit is also coupled from the length of waveguide for detecting on a continuing basis the temperature of the substance which is usually liquid being heated by the microwave energy.