Rf test load and method for internal use thereof

Abstract

The invention describes an internal test load and method for forming an internal test load which is adapted to absorb energy from a power source such as an RF transmitter, transceiver, or amplifier. The test load is positioned internally within a housing, and includes at least one impedance device, such as a power resistor, coupled to the power source which is matched to the impedance thereof. The impedance device is supported on a heat sink which is adapted to absorb heat generated by the impedance device so as to be distributed over a relatively large area constituting the heat sink. The heat sink is positioned in spaced part relation to the housing, and is not directly supported or secured to the housing. A potting material surrounds the load assembly and supports the heat sink, wherein the heat sink effectively 'floats' within the potting material such that heat absorbed by the heat sink will not be directly transferred to the housing, but will be dissipated through the potting compound. As an example, the internal test load is applied to an RF watt meter for testing low power RF transmitters, transceivers and RF amplifiers without an external load or antenna connected separately thereto. The test load may be mounted on a heat sink comprising an aluminum plate having a significant thickness. The potting material may be a strong, lightweight epoxy material, which may include a large number of air pockets therein, to facilitate dissipation of heat from the heat sink and to slow the transfer of heat to the housing in which the internal test load is positioned.