Abstract: This invention relates to electronic circuit packages designed to hold high frequency circuits operating particularly, but not exclusively, in the microwave, millimeter wave, and sub-millimeter wave bands. The invention provides a package incorporating a cavity in a material for containment of the circuits, wherein the package further incorporates at least one conductive surface mounted on an inner surface extending into the cavity, the conductivity thereof being adapted to be at least partially absorbent to electromagnetic radiation. The conductive surface according to the present invention will tend to attenuate electromagnetic radiation present within the cavity, and so help to prevent undesired coupling from one point to another within the cavity. The conductivity of the conductive material is preferably arranged to match the impedance of the radiation mode estimated or computed to be present within the cavity.

Abstract: A receiver front end is provided capable of receiving electromagnetic wave signals having frequencies in the range of substantially 35 GHz to substantially 40 GHz, and having a gain of substantially 24 dB or above and a noise figure of substantially 4 dB or below, and comprising one or more multifunction monolithic microwave integrated circuits (MMICs). The receiver front end preferably has a noise figure of substantially 4 dB or below over an output signal frequency range of substantially 1 to 10 GHz, and a size in the region of 30 mm2 or less. The reveiver front end may comprise a receiver MMIC, and a doubler/buffer amplifier MMIC. The receiver MMIC may comprise a low noise amplifier (3), a mixer (5), a filter (4) and an intermediate frequency amplifier (6).