Second harmonic suppressor for power amplifier tank circuit
US4334203A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 9, 1980 |
| Grant date | Jun 8, 1982 |
| Priority date | — |
| Expiry date | Apr 9, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01P7/04
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A device to suppress the generation of second harmonic frequencies in a power amplifier tank circuit such as may be used in a radio frequency transmitter. The present invention employs a device connected between the outer conductor (which is normally at ground potential) and the inner conductor. Specifically, the device utilizes a metal strap, such as a copper strap, which is connected to the inside surface of the outer conductor in an electrically conductive manner and which is also connected to a capacitor disk movably mounted with respect to the inner conductor. The capacitor disk is mounted to an insulating arm or rod and may be projected back and forth within the space between the outer and inner conductors, thereby adjusting the impedance of the device. By sliding the rod toward the inner conductor, the loop formed by the copper strap becomes more straightened thereby changing the inductance of the circuit. The suppressor is mounted at a point in the tank cavity which is an RF null point for the fundamental frequency. At this point, the second harmonic exhibits a predominantly high impedance and high voltage and thus can be suppressed with this simple LC arrangement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.