Abstract: A radio for use in microwave datalink applications in which a common local oscillator is used for both a final radio frequency (RF) up-converter stage and an initial RF down converter stage. The frequency of the common local oscillator corresponds to an integer multiple of a local oscillator needed for an earlier up-converter or later down converter stage. The circuit can be used to provide a radio frequency carrier in a 30 GHz band using Coaxial Resonator Oscillators (CRO's) that lend themselves to a planar microstrip circuit implementation.

Abstract: A dielectric fill disposed in a waveguide is used to form an antenna feed. One attribute of the dielectric fill is to enable a reduction in aperture size that in turn increases the beamwidth. More specifically, an RF signal received or transmitted at the end of the waveguide can have a wider half-power beamwidth angle than otherwise achieved without the dielectric filling the waveguide. A portion of the dielectric fill may protrude beyond the end of the waveguide to match the waveguide to free space. If the waveguide section is cylindrical in cross-section, a transformed section formed of an annular dielectric ring may be used to match the feed to a rectangular waveguide.

Abstract: A communication transceiver circuit intended for operation in a Time Division Duplex (TDD) system. The configuration eliminates the need for transmit-receive switches and the circuitry needed to operate them. Instead, a three port circulator is used to couple a transmitter section and receiver section to a common antenna. A signal power detector and blanking circuit are coupled to the receiver section input and arranged to generate a blanking signal for an input receiver amplifier. This disables the receiver during conditions when power reflected back through the antenna and circulator would otherwise saturate the receiver. In a preferred environment, a second circulator is connected to an intermediate frequency (IF) side of the transceiver together with a pair of isolators to permit the transceiver to be connected to IF equipment with a single cable.

Abstract: A point-to-point microwave radio link that operates in a Frequency Division Duplex (FDD) mode using direct digital modulation with an ON-OFF Keyed (OOK) scheme. The transmit signal is generated by a circuit that uses an oscillator operating in a microwave radio band. The oscillator output is switched at the input bit rate. The output of the switched oscillator is then frequency multiplied by the predetermined factor to produce the modulated microwave output signal at the desired band.

Abstract: A point-to-point microwave radio link that operates in a Frequency Division Duplex (FDD) mode using direct digital modulation with a Continuous Phase Shift Keyed (PSK) scheme. The transmit signal is generated by a circuit that uses a Voltage-Control Oscillator (VCO) operating in a microwave radio band to obtain the modulated signal. The VCO output is fed to a phase modulator to obtain the modulated signal. The output of the VCO is then frequency multiplied by the predetermined factor to produce the modulated microwave output signal at the desired band.

Abstract: A point-to-point microwave radio link that operates in a Frequency Division Duplex (FDD) mode using direct digital modulation with a Continuous Phase Shift Keyed (PSK) scheme. The transmit signal is generated by a circuit that uses a Voltage-Control Oscillator (VCO) operating in a microwave radio band to obtain the modulated signal. The VCO output is fed to a phase modulator to obtain the modulated signal. The output of the VCO is then frequency multiplied by the predetermined factor to produce the modulated microwave output signal at the desired band.

Abstract: A point-to-point microwave radio link that operates in a Frequency Division Duplex (FDD) mode using direct digital modulation with a Continuous Phase Shift Keyed (PSK) scheme. The transmit signal is generated by a circuit that uses a Voltage-Control Oscillator (VCO) operating in a microwave radio band to obtain the modulated signal. The VCO output is fed to a phase modulator to obtain the modulated signal. The output of the VCO is then frequency multiplied by the predetermined factor to produce the modulated microwave output signal at the desired band.

Abstract: A compact lightweight antenna for receiving microwave direct line of sight wireless data signals used in services such as Local Multipoint Distribution Services (LMDS). The antenna provides for precise control over isolation of polarized signals. The antenna consists of an external parabolically shaped dome formed of a suitably resilient material such as thermoplastic. A polarizing conductive grating is formed on the interior surface of the dome and serves as a transreflector for initially passing received radiation having a vertical polarization. A twist reflector disposed at a point along an axis defined by the conductive grating reflects the received radiation, back in the direction of the transreflector with a different polarization. The now differently polarized energy is reflected by the parabolically shaped conductive grating at a feed point located in the center of the twist plate.

Abstract: A system for providing network management access to RF outdoor units of a point-to-multipoint wireless network. Network management signals from a network management system (NMS) are transmitted from an outdoor unit (ODU) receiver to destination ODU transmitters via modulation of a low frequency carrier over a frequency reference interconnection carrying a frequency reference signal. The frequency of the carrier is lower than the frequency reference avoiding any interference between the signals.

Abstract: A point-to-point microwave radio link that operates in a Frequency Division Duplex (FDD) mode using direct digital modulation with a Continuous Phase-Frequency Shift Keyed (CP-FSK) scheme. The transmit signal is generated by a circuit that uses a Voltage-Control Oscillator (VCO) operating in a microwave radio band. The VCO is deviated over a narrow frequency range that is reduced by a predetermined factor. The output of the VCO is then frequency multiplied by the predetermined factor to produce the modulated microwave output signal at the desired band. The deviation frequency of the VCO is thus chosen to be the reciprocal of the multiplication factor times the transport bit rate.

Abstract: A compact lightweight antenna for receiving microwave direct line of sight wireless data signals used in services such as Local Multipoint Distribution Services (LMDS). The antenna provides for precise control over isolation of polarized signals. The antenna consists of an external parabolically shaped dome formed of a suitably resilient material such as thermoplastic. A polarizing metal grid is formed on the interior surface of the dome and serves as a transreflector for initially passing received radiation having a vertical polarization. A twist reflector disposed at a point along an axis defined by the metal grid reflects the received radiation, back in the direction of the transreflector with a different polarization. The now differently polarized energy is reflected by the parabolically shaped metal grid at a feed point located in the center of the twist plate. Operation for transmitting energy is analogous.

Abstract: A method of forming a circuit includes forming a metallic circuit pattern on a base substrate. The circuit pattern has traces which are connected together by temporary bussing. A resist pattern for defining at least one terminal pad is formed over the circuit pattern. A layer of metal is formed on at least one area of the circuit pattern exposed by the resist pattern to a thickness suitable for serving as the at least one terminal pad for the circuit. A portion of the base substrate at the location of the temporary bussing is removed thereby causing the removal of the temporary bussing.

Abstract: A technique for manufacturing a domed housing, including a transreflector element for use in a microwave antenna. The dome incorporates a metallic polarizing grid as part of a complex curved shape using an insert mold process. As a result, the transreflector component can be inexpensively formed as an integral part of the supporting structure and any alignment features, without the need for additional molding steps or multiple component parts.