Abstract:
A bypass capacitor is arranged at an end of a main surface of a circuit board. More specifically, the bypass capacitor is arranged at the end of the main surface of the circuit board such that conductor pattern is located closer to the end of the circuit board than earth pattern. In this position, an earth pattern and a through hole electrode do not surround an outer side of a power supply line. Arrangement of the bypass capacitor in this position can particularly suppress radiation noises that may emerge from a resonance end surface of the board. Therefore, it is possible to provide a circuit unit, a power supply bias circuit, an LNB and a transmitter capable of suppressing oscillation at a certain frequency that cannot be sufficiently suppressed by a conventional bypass capacitor.
Abstract:
A high-frequency circuit includes: a first earth pattern provided on a second main surface of a dielectric substrate; a signal pattern provided on a first main surface of the dielectric substrate and configuring a microstrip line together with the dielectric substrate and the first earth pattern; a second earth pattern provided on the first main surface and spaced from the signal pattern; a metal member electrically connected to the second earth pattern, and facing the signal pattern with a spacing therebetween; and a metal casing electrically connected to the first earth pattern and the second earth pattern, and housing the dielectric substrate, the microstrip line and the metal member.
Abstract:
An LNB converter includes a first frame made of metal and having an edge, and a second frame made of metal and having an opposite portion opposed to the edge. It also includes a dielectric substrate arranged in a space surrounded by the first frame and second frame. The dielectric substrate includes a conductor pattern formed at a surface of the dielectric substrate. The edge and the opposite portion are fixed together by a seal member. A cushion member is arranged between the edge and the opposite portion. The cushion member is arranged to prevent the seal member from entering the space surrounded by the first frame and second frame and coming into contact with the dielectric substrate.
Abstract:
A local oscillator has the following construction so that easier design can be achieved, stable oscillation characteristic can be provided and the manufacturing cost can be reduced. A high impedance line, a ground pattern with a through hole, and a coupling line are formed on a printed circuit board. A chip part, such as HEMT, and a dielectric resonator are mounted thereon by die bonding. A terminal of HEMT is connected to the pattern formed on the printed circuit board by wire bonding. A drain terminal of the HEMT is connected to a bias circuit. The bias circuit includes a stub for grounding, a high impedance line, and a chip capacitor.
Abstract:
A rat race circuit has an annular transmission line formed on a microstrip dielectric substrate. A terminal for port 1 is formed at any given position of the annular transmission line. Respective terminals for port 2 and port 3 are formed at respective positions distant from the position of port 1 in the counter-clockwise and clockwise directions each by a distance of λg/4 (λg: effective wavelength). Moreover, at the position distant from the position of port 2 in the counter-clockwise direction by the distance of λg/4, a terminator resistor (R=50Ω) is formed. A local oscillator signal is supplied to port 1, and first and second mixer inputs are connected respectively to port 2 and port 3. The local oscillator signal divider and a low noise converter using the divider are thus provided that are scarcely influenced by matching with respect to mixers and provide stable performance and high isolation.
Abstract:
In a low-noise amplifying device, an antenna point is attached to a tip portion of a microstrip line and an end surface of a printed wiring board. The printed wiring board is fixed to a chassis by a screw, a rivet, a projecting portion of a frame or a conductive adhesive in the vicinity of a connection of the antenna pin to the microstrip line. Thereby, even a slight warp that might exist on the board is corrected, so that adhesion between the board and the chassis is reinforced and the low-noise amplifying device stably operates.