Abstract: A frequency converter for use in a 4 GHz-band comprising a printed circuit board and a shield case. The printed circuit board is provided in the shield case and composed of an input terminal, and successively, a circuit of low noise amplifier, a band pass filter, a mixer and a circuit of local oscillator connected to the mixer. The constitution of the frequency converter is simplified, and accordingly the mass productivity, yield of production and reliability of the fabricated converter are greatly improved.

Abstract: A tuner for a television receiver is designed for minimal size and to have a series of external terminals placed along one side thereof. An electronic tuning section including several local oscillator circuits is located within a common shielding case and a phase locked loop channel selection circuit is also located within the case in an isolated compartment thereof. The channel selection circuit and the local oscillator circuits all lie along a straight line parallel to and adjacent one end of the case.

Abstract: A receiver stage for radio or television receiver. A single case enclosing a device comprises inside a tuner, an intermediate frequency amplifier connected to the tuner, a demodulator connected to the intermediate frequency amplifier, and a phase locked loop provision connected to the tunner. The joint case allows joint shielding of all components with shield plates mounted inside the case, avoids unreliable plug connections and reduces the production cost of radio and television receiver sets.

Abstract: A portable radio housing has a shield that provides electromagnetic isolation between logic and radio boards operating on close frequencies. The radio board is positioned in a conductive frame having fours sides surrounding a central opening. A tab on the frame is connected to a power module on the radio board to sink heat from the power module. A middle shield having sides with integral spring fingers at calculated intervals is attached to the frame over the rear surface of the radio board. A logic board and rear shield are attached to the frame over the middle shield. A connector protrudes through an opening in the middle shield and interconnects the logic and radio boards. A front shield, also having sides with integral spring fingers, is attached to the frame over the front surface of the radio board. The front shield has an integral speaker baffle and tabs for holding a connector. An outer housing and keypad/display module enclose the frame.

Abstract: A compact or miniaturized well-shielded double superheterodyne tuner is provided, wherein an input circuit portion, a first mixing portion, a first intermediate frequency bandpass filter, a second mixing portion and an output circuit portion are mounted in separated casings. The first mixing portion and the second mixing portion are provided on printed boards and each mounted on a bottom plate of the casing. The casings containing the first and second mixing portion are arranged in a manner such that grounded surfaces of the printed boards contained in the casings are arranged face to face. The casing containing the bandpass filter is contacted adjacently to a common face of the face to face casings. Each of the casings containing the input and output circuit portions is located adjacently to each of faces common to the face to face casings and the filter containing casing. Some structual improvements are also provided for simplifying the manufacture and adjustment of the tuner.

Abstract: The invention relates to a flat pack or housing for a radio apparatus having a rectangular cross-section comprising an opening at the front side and an opening at the back side which are respectively closable with a cover and also relates to a support mount for the radio apparatus. Such a radio apparatus provides the user with the possibility of versatile use at various use locations and is securable in a receptacle. To this end, the housing is divided into two tub-shaped main chambers by a bottom plate oriented parallel to the plane of the openings. The individual assemblies of the radio apparatus are disposed RF-shielded in the main chambers and the main chambers being closed by the covers by means of a central screw. Outside guide rails for acceptance into the support mount are disposed at opposite lateral faces of the housing. The support mount is composed of a sheet metal panel bent at three sides.

Abstract: A microwave integrated circuit comprises a shield case having a pair of opposed first and second end walls, a pair of side walls and top and bottom walls, and a dielectric substrate on the bottom wall. First and second interconnected integrated circuit portions are arranged on the substrate between the first and second end walls. An input strip line is arranged on the substrate, the strip line having one end coupled to the input of the first integrated circuit portion and the other end terminating at a position spaced from the first end wall by a distance approximately equal to an integral multiple of the half wavelength of a signal propagating in the shield case. An elongated coupling member is disposed in parallel with the first end wall, the coupling member extending from the other end of the input strip line to an external circuit.

Abstract: The disclosure describes an improved CATV converter that incorporates an intermediate frequency filter and amplifier unit that includes first and second tunable circuits. Each tunable circuit has a fixed capactive element and a variable inductance means for tuning the tunable circuit. The first and second tuned circuit are transmissively coupled to one another through a slit in a shield which otherwise shields one tunable circuit from another. The intermediate frequency filter and amplifier unit also includes an FET for amplifying a narrow band intermediate frequency signal and a third tunable circuit comprising the output capacitance of the FET and a variable inductance means for tuning the third tunable circuit.

Abstract: A CATV converter of a dual frequency conversion type is constructed in a chassis divided into compartments for accommodating respective stages between the input and output terminals. The primary and secondary local oscillators are disposed apart with other compartments interposed therebetween thereby to enhance the input to output isolation.

Abstract: A cable television up-down tuner includes a first frequency up conversion stage in which a first local oscillator, tunable over a wide frequency range, is coupled to a ring diode mixer having individual biasing networks in series with each diode. A combination high pass and low pass filter provides a bandwidth coupling of input signals to the mixer. An intermediate frequency amplifier couples the up converted signal to a second mixer. A fixed tuned second local oscillator down converts the intermediate frequency signal to a selected television channel frequency. The first local oscillator includes a printed circuit board transmission line resonator which is tuned by a varactor diode. The two local oscillators are positioned adjacent the corners of a quadrilateral housing and are isolated from each other by three wall-type shields.