Abstract:
A dielectric filter in which the resonant frequency of each resonator and the degree of coupling between resonators can be adjusted independently. The dielectric filter includes first and second dielectric blocks, each having a through bore. The dielectric blocks, including the bores, are covered with a conductive film to define respective dielectric resonators whose electric energy component varies in the direction of an axis of the through bore. A first isolated coupling electrode is formed on the first dielectric block for coupling an input signal to the first dielectric resonator. A second isolated coupling electrode is formed on the first dielectric block in a location with a relatively high electric energy component so that electric energy exits the first dielectric block via the second coupling electrode. The second dielectric block has a third isolated coupling electrode at a location corresponding to the second coupling electrode such that electric energy leaving enters the second dielectric block via the third coupling electrode and sets up an electromagnetic field in the second dielectric block whose electric energy component varies in the direction of the through bore of the second dielectric block. A fourth isolated coupling electrode is formed on the second dielectric block at a location with a relatively high resonant electric energy component such that electric energy leaves the dielectric block via the fourth coupling electrode.
Abstract:
There are provided a dielectric filter that shows a large effective bandwidth and a method of regulating the frequency bandwidth of a dielectric filter in order to achieve a large effective bandwidth, in which the dielectric filter comprises a dielectric ceramic block provided with three or more resonators arranged in parallel with each other and formed by respective resonant conductors, capacitive electrodes are provided at a position close to an electrically open-circuit end surface on one of four lateral surfaces of the dielectric ceramic block to respectively lie over the adjacently disposed resonant conductors, and a shield electrode provided on the lateral surface is partly removed at a position bordering the open-circuit end surface where the capacitive electrodes are located in order to form an insulation gap having a predetermined width.
Abstract:
A filter for processing electromagnetic signals has a housing with resonators located inside the cavity of that housing. The resonators, which may be made in part from superconducting material, have rounded exterior surfaces without corners to provide a more desirable coating surface and uniform electric field around the resonators. The filter housing may be composed of a plurality of housing cells, each containing a resonator. These cells can be removably attached to other cells so that resonators may be added to or removed from the filter as may be required for a particular application.
Abstract:
A high power tunable filter, for use in a frequency hopping system, is described and includes a transmission line having an input for receiving a high power level input signal to be filtered, and an output. The filter includes a plurality of resonators, each parallel-coupled to the transmission line, and driven by an associated electronic tuning network. Each of the electronic tuning networks includes a plurality of tunable reactive elements and PIN diodes, each PIN diode connected to one of the tunable reactive elements to enable this diode to connect its associated tunable reactive element in and out of the tuning network, thereby controlling the resonant frequency of the resonator associated with the tuning network. An electronic control circuit is also provided for controlling the frequency of the tunable filter. The electronic control circuit includes appropriate input circuitry for entering a desired frequency of the tunable filter, and an addressable look-up table responsive to the input circuitry for converting the desired frequency into a unique binary codeword. Switch drive circuits are also provided, responsive to the bits of the binary codeword, for controlling the operational states of the PIN diodes.
Abstract:
For suppression of high-frequency spurious signals (noise) present on an electrical transmission line, the line incorporates at least one section comprising a distributed low-pass filter. This section is constructed so that its wave impedance (Z.sub.1) has a different value than the wave impedance (Z.sub.0) of the neighboring line sections. This filter line section additionally provides considerable dielectric losses and/or skin effect losses. At both ends of the filter line section, at which the wave impedance changes, multiple reflections arise that attenuate the high-frequency spurious signals (noise). The dielectric or skin effect losses produce strong attenuation of the undesired resonances that arise from the reflections, as well as further attenuation of spurious signals in the highest frequency region.
Abstract:
There is provided a resonator comprising principally a hollow metal finger integral with the wall of a guide or a cavity. A metal plunger, coated with a fine dielectric layer, of fairly low permittivity, is able to slide inside the hollow metal finger to cause the tuning frequency of the cavity or the susceptance coupled to the guide to be varied. This layer may be formed from Teflon.
Abstract:
A high frequency filter for frequencies higher than the VHF band comprising at least one resonator has been found. Each resonator comprises a conductive housing, an inner conductor one end of which is fixed at the bottom of the housing and the other end of which is free standing, a cylindrical dielectric body surrounding said inner conductor, and the diameter of the dielectric body is approximately four times as large as that of said inner conductor.