A selectable band-pass filtering apparatus for use at the input of analysis instrumentation, such as a spectrum analyzer for testing a multi-channel communication system, comprises a high-pass filter section including a plurality of separate high-pass filters, each characterized by a respective high-pass cut-off frequency within a predetermined input frequency spectrum characterizing the communication system and a low-pass filter section including a plurality of separate low-pass filters each characterized by a corresponding low-pass cut-off frequency within the input frequency spectrum. The apparatus further comprises switching devices capable of connecting a selected high-pass filter In series with a selected low-pass filter in order to select passband having center frequency and bandwidth characteristics defined by corresponding high-pass cut-off frequency and low-pass cut-off frequency.

Selectable band-pass filtering apparatus and method

A television receiver includes a single tuner for tuning both television channels and broadcast FM stations. The tuner is operated at a fixed gain setting in FM reception mode. The tuner serves as the first conversion stage of a double conversion FM receiver, wherein the mixer of an FM radio integrated circuit serves as the second conversion stage. The arrangement operates at a specific and non-arbitrary first IF frequency. The FM receiver is also capable of automatically receiving National Weather Service broadcasts on that one of NWS's seven allocated frequencies which is operating in a listener's area. The receiver provides an on-screen display of the currently tuned FM channel number.

Using a first IF of 43.5 MHZ or less in an FM radio in a television tuner

A method and apparatus for detecting a collision between signal transmissions on a carrier medium, such as UTP wiring, are described. The method commences with the transmission of an identifier from a transmitter of a network device. The transmitted identifier has a predetermined duration and includes a pulse at a temporal location within the transmitted identifier specific thereto. A identifier is also received at a receiver of the network device. The received identifier also has a predetermined duration, and includes a pulse at a temporal location therein. A determination is then made as to whether the temporal location of the pulse within the received identifier corresponds to the temporal location of the pulse within the transmitted identifier. If not, a collision is detected on the network.

Method and apparatus for detecting collisions on a network using multi-cycle waveform pulses

A filter arrangement, for shaping a signal transmitted over POTS wiring, includes an input to receive a signal. The filter arrangement includes a signal path from the input to an output that is coupled to POTS wiring. The transmit path includes a high-pass filter, a low-pass filter, and a trap filter coupled between the high and the low-pass filter. The trap filter operationally introduces a filter zero at a resonant frequency of the high-pass filter.

Filter arrangement for shaping a pulse propagated over pots wiring, and a method of manufacturing the same

A laminated LC filter includes inductors of a low-pass filter and an inductor of a trap circuit, which are disposed in different layers in the lamination direction of the insulator sheets. Inductor via-holes are connected to each other in the lamination direction of the insulator sheets to define columnar inductors. The inductor via-holes are electrically connected in series with coil-shaped conductor patterns to define inductors, respectively. The others of the inductor via-holes are electrically connected in series with a coil-shaped conductor pattern to define an inductor. Moreover, an inductor via-hole singly defines a columnar inductor.

LC filter circuit, monolithic LC composite component, multiplexer, and radio communication device

A bandpass filter for a CATV converter is of the structure with a low-pass filter section with low-pass filters connected longitudinally in a plurality of stages and a high-pass filter section, and comprises a variable trap circuit including a varactor and an inductor, and another varactor connected to one of the capacitors belonging to the low-pass filter section. Capacitances of these varactors are controlled by a tuning voltage so as to eliminate the various problems which would occur in a double-balance mixer to be connected at a later stage in the CATV converter.

Syuuji Matsuura

Papers

Bandpass filter for a CATV converter