Abstract: The disclosure relates to an improved coaxial resonator and an electrical filter employing such coaxial resonators. The electrical filter includes a casing of electrically conductive material, at least more than one coaxial resonators, for example, 1/4 wavelength coaxial TEM resonators each having dielectric member disposed between inner conductor and outer conductor of the coaxial resonator and a terminal electrode secured in the inner conductor to provide a terminal portion projecting from an open end face of each of the coaxial resonators, and accommodated in the casing so as to be electrically connected and mechanically secured to the casing, and coupling members for electrically coupling the resonators to each other at the terminal portions and also to input and output connectors for said electrical filter.

Abstract: A resonant circuit phase equalizer includes two quarter-wavelength-long strip conductors extending in parallel from adjacent ends of respective input and output strip conductors of a microwave stripline transmission line. A fixed MIS direct-current-blocking and radio-frequency tuning capacitor is connected across the remote ends of the quarter-wave strip conductors. A variable varactor capacitor is connected across the near ends of the quarter-wave strip conductors. A variable direct-current bias voltage is applied through radio frequency choke conductors to the varactor to vary the capacitance thereof and the center frequency tuning of the equalizer.

Abstract: A microwave filter comprising within a conductive casing, a plurality of resonant transmission lines arranged parallel between opposed end walls of the casing, a plurality of shielding members each located between adjacent transmission lines, and a capacitive interstage coupling member disposed transverse to the transmission line. The interstage coupling member comprises a dielectric member and a plurality of conductive regions arranged successively thereon so as to establish capacitive coupling between adjacent conductive regions. Each transmission line is connected at one end to a side wall of the casing and supported at the other end by the dielectric member in electrical contact with a respective one of the conductive regions, whereby the interstage coupling between the transmission lines is provided by the capacitively coupled conductive regions.

Abstract: Frequency division of microwave signals may be done using heterodyne conversion but there are limits to the ultimate instantaneous bandwidth that can be down-converted using this method and any frequency aberrations of the local oscillator show up at the output. It is also known to down-convert microwave signals by using a varactor divide-by-two system. However, to divide by factors greater than two, these dividers must be cascaded which results in losses that must be compensated by amplifiers. The present invention alleviates the foregoing problems by providing a single-stage analog microwave frequency divider which will divide microwave signals by four. The divider comprises a substrate having an input microstrip transmission line capacitively coupled to a resonator formed of first and second spaced apart parallel microstrip transmission lines of predetermined length.

Abstract: A microwave device is disclosed comprising a microstrip line pattern including an open ring forming a 1/2.lambda. resonator having a narrow gap in which the electromagnetic field is closely tied to the ring.

Abstract: A variable resistance device in the form of a PIN diode is connected between one of a pair of input terminals and one of a pair of output terminals, and the other input and output terminals are connected to a common terminal.A distributed constant line is connected between the output terminal of the PIN diode and the common terminal, and variable capacitance diodes are connected between the opposite ends of the distributed constant line and the common terminal. By applying a control voltage applied to the PIN diode and the variable capacitance diodes, the steepness and the center frequency of the variable resistance device are varied.

Abstract: A circuit capable of providing the negative resistance heart of oscillators or amplifiers in the 5-20 Gc/s frequency band, comprising a central resonant cavity and one or several peripheral exciting chambers, each containing a push-pull arrangement of two diodes for example three pairs of diodes in chambers arranged at 120.degree. from one another on a circle concentric to the central cavity. The diodes are located at the bottoms of cylindrical exciting chambers communicating with the central chamber through holes situated at the center of each push-pull arrangement. Each pair of diodes is maintained and polarized by a metallic bar which plays, with the walls of the exciting chamber, the role of an impedance transformer between the diodes and the central cavity. The metallic bar is maintained by a polarization rod penetrating the chamber through an insulating passage.

Abstract: A removable diode package for mounting beam-lead diodes in coaxial, stripline or waveguide microwave circuits is described. The diode package is capable of operation at frequencies above 40 GHz. A low-dielectric polyimide insulating washer is used to reduce parasitic elements normally associated with diode packages at microwave and millimeter frequencies.

Abstract: Compactness and substantially optimum electrical performance are realized in a microwave filter incorporating a housing (21, 22) including an interior surface that forms an enclosed cavity having planar cross sections substantially elliptical in shape (FIG. 3). At least one axis of each ellipse monotonically increases in length with perpendicular distance from a first surface (23) toward a second surface (24). A dielectric resonator (11) is positioned in a predetermined relationship within the cavity and at least two terminal members (30,35) extend from outside the housing (21,22) into the cavity. Electromagnetic coupling between the housing (21,22) and the dielectric resonator (11) is minimized to afford substantially optimum electrical performance of the microwave filter.

Abstract: An electrical filter comprising a cylindrical metal case having an aperture extending in a line, a plurality of 1/4 wave length transverse electromagnetic mode coaxial resonators inserted in the aperture of the metal case in an electrical series fashion, each resonator including a dielectric resonator comprising a cylindrical dielectric material, an outer conductor and an inner conductor, the open circuit ends of the adjacent dielectric resonators being capacitively coupled and the short circuit ends of the adjacent dielectric resonators being inductively coupled by means of a coupling electrode having a coupling window. Preferably, a portion of the dielectric material having a lesser influence upon the fundamental mode is made in a lower dielectric constant to improve the spurious response characteristic.

Abstract: An electrical filter network with improved characteristics is disclosed for selectively attenuating and passing two different, closely spaced frequencies. The notch filter network includes a low Q reactive circuit tuned to be parallel resonant at the frequency to be attenuated. A cavity resonator with a high Q is inductively coupled to the reactive circuit and is tuned to be resonant at the frequency to be passed. Utilizing these concepts, a multicoupler may be constructed to consist of two or more such filter networks in combination with a transmission line. In such a multicoupler, the network adjacent to the antenna terminal is separated therefrom by a multiple of a half wavelength. Additional filter networks are separated from one another by an odd number of a quarter wavelength. With this arrangement, each network passes a band around the frequency to which the high Q cavity is tuned and rejects a band of frequencies around the reactive circuit resonant frequency.

Abstract: A building block resonator is fabricated using a single chemically milled copper pattern and two pieces of garnet material to form a quarter-wave transmission line which is shorted at one end. Tuning is achieved with an electromagnet by varying the static magnetic field perpendicular to the resonator which causes the permeability of the garnet material to change. Resonators formed in this manner can be cascaded in any number to form a multi-pole filter. Narrow band UHF filters (0.5 percent 3 dB bandwidth at 225-400 megahertz) can be built in a very compact form. The magnetic tuning field intensities used are above the saturation point of the garnet, and high power level operation devoid of non-linear effects is possible.