Abstract: A waveguide filter capable of operating at high power levels while retaining substantially constant filter characteristics over a wide temperature range. Two cylindrical body portions of a metal having a low temperature coefficient expansion are sandwiched between three highly thermally conducting iris members, each of which has an aperture of predetermined dimensions for determining the wave modes which propagate through the filter. Each iris member extends beyond the adjacent bodied portion to heat dissipating means which may either be cooling fins through which air is circulated or cooling coils through which a cooling fluid is circulated. Because the proportion of the total filter length occupied by the iris members is much smaller than that of the body portion, very little elongation takes place as the filter cavity is heated thus resulting in temperature-stable filter characteristics.

Abstract: There is herein described a microwave coupled-cavity filter having adjacent cavities defined by spaced end walls disposed in a tubular side wall, the end walls including at least one pair of oppositely disposed coupling apertures extending radially from the side wall toward the center of the associated end wall, and at least one of the associated pair of the coupling apertures containing a tuning screw extending through the side wall for precisely adjusting the coupling between adjacent filter cavities.

Abstract: Multiple coupled high Q cavities are used to generate odd order elliptic function band-pass filters using a minimum number of cavities connected by simple and resonant coupling elements. A specific embodiment of a 3-pole, 20 MHz band-pass wave guide cavity filter centered at 3890 MHz is disclosed. Couplings between cavities may be either on the end walls or the side walls. The simple coupling elements may be simple coupling holes, and the resonant coupling elements may be a non-shorting screw in a window between cavities.

Abstract: A waveguide filter is herein described that employs a resonator ordering which allows a direct realization of all canonical couplings while retaining the advantages of a standard dual mode filter, the filter including a reflective plate in one end cavity and both input and output ports in the other end cavity, where one of the ports is a shunt port in a sidewall of the cavity structure and the other port is a coupling slot in the outer end wall.

Abstract: A microwave distributed-constant filter of a band-pass characteristic having at least one attenuation pole comprises resonator rods, each of which has an open and a shorted end and of which two first are inductively coupled in series through at least one second resonator rod. The first resonator rods are capacitively coupled direct to each other with a projection attached adjacent on at least one of the first resonator rods to the open end thereof. The first resonator rods may be coupled directly to input and output terminals of the filter. Alternatively, two third resonator rods may be interposed between the respective ones of the first resonator rods and the input and the output terminals. The third resonator rods may be inductively coupled direct to each other.

Abstract: In a band pass filter having a plurality of helical resonators each including a quarter-wavelength winding, at least two of the helical resonators are substantially shielded from each other by a partition wall, while the corresponding two quarter-wavelength windings which are shielded from each other are electrically connected to each other through a lead line which is insulated from the shield casing, thereby improving the cut off characteristic of the filter to cut off the applied signal more rapidly in the high frequency region of the band being filtered than in the low frequency region.

Abstract: Apparatus for the generation and radiation of microwave radiation including a microwave oscillator having a cavity resonator directly coupled with the input of a horn resonator by way of a first apertured diaphragm. There is arranged within the horn radiator a second apertured diaphragm disposed at a distance from the first apertured diaphragm such that together with the first diaphragm it forms a filter resonator.

Abstract: A filter for very short electromagnetic waves is disclosed in which a plurality of resonators are formed in a row with each resonator containing two filter circuits. The resonators are operated in a dual mode and the filter circuits are arranged in an electrical sequential manner. First and last filter circuits in a direction of the transmitted energy are provided with input and output lines, respectively. At least one additional coupling is provided between at least two filter circuits which do not directly follow one another in electrical sequential fashion. At least one of the resonators provides two filter circuits which are not adjacent with respect to one another in electrical sequential fashion and are coupled via an additional coupling.

Abstract: A filter for very short electromagnetic waves having a plurality of resonators which are coupled to one another and which are operated in the dualmode. The first and last resonators, as viewed in the direction of energy transmission, are provided with connection lines for the supply and discharge of electromagnetic energy. An additional coupling is provided between at least two filter circuits which are not directly consecutive in the electrical mode of operation and the individual resonators are arranged in juxtaposed rows. The resonators are arranged to be mechanically symmetrical relative to the center of the circuit, and the equivalent circuit diagram on which the construction is based is selected to be asymmetrical in respect of the element values, in such a manner that the number of additional couplings agrees with the theoretically determined, minimum number of additional couplings.

Abstract: Filtering device comprising a microwave band-pass filter with resonant cavities tunable by a single mechanical control shaft, an additional resonant cavity which is also controlled by this single control and which is tuned to a frequency shifted by a fixed value in relation to that of the other cavities, and a servocontrol mechanism for controlling the tuning of this additional cavity in dependence upon a frequency, for instance that of the local oscillator of a frequency converter, the simple storage of this frequency ensuring the tuning of the band-pass filter.