Abstract: A receiver is provided with a surface elastic wave amplifier of a parametric amplification type within an HF amplifier unit, and with a circuit for providing pumping power for said surface elastic wave amplifier from oscillating outputs of an IF converting local oscillator of the receiver.
Abstract: RF-input stage for TV receivers comprising a field effect transistor in grounded source circuit configuration and a frequency-dependent coupling network arranged between the gate electrode of the field effect transistor and an aerial input for selecting TV signals and transforming the signal impedance. The frequency-dependent coupling network is terminated with a resistor which is arranged between the gate electrode of the field effect transistor and ground and whose value has been chosen so that on the one hand this resistor terminates in conjunction with the input impedance of the field effect transistor the frequency-dependent coupling network with an acceptable reflection factor and on the other hand forms in conjunction with the output impedance of the frequency-dependent coupling network an impedance at which the noise contribution of the field effect transistor is at least substantially at its lowest.
Type:
Grant
Filed:
October 7, 1981
Date of Patent:
November 8, 1983
Assignee:
U.S. Philips Corporation
Inventors:
Johannes H. Hendriks, Johannes J. M. Van Daal
Abstract: A diplexer comprises a first frequency selective filter coupled between its first input terminal and a circuit point, a second frequency selective filter coupled between the circuit point and its output terminal, and third frequency selective filter coupled between its second input terminal and the circuit point. The first filter selects frequencies higher than a first frequency and the second filter selects frequencies lower than a second frequency which is higher than the first frequency. The third filter selects frequencies lower than a third frequency which is lower than the first frequency. In a television receiver, the first and second filters serve as a bandpass filter for the UHF band, and the third filter passes the VHF and CATV bands.
Abstract: A radiated input mixer for converting a radio frequency (RF) signal into an intermediate frequency (IF) signal with the aid of a local oscillator (LO) signal includes, in combination, an antenna having balanced feed terminals, a diode quad, and a balun with balanced terminals orthogonally positioned with respect to the antenna terminals to provide a less complex and more efficient device of the type described than has heretofore been known in the art.