Abstract: A solid state power amplifier which combines the output of several power modules by means of a waveguide radial combiner. The physical structure of the amplifier is such that the power modules lay flat on a planar heat sink which can be easily cooled by forced air. The input power can be distributed to the power modules by means of a microstrip divider. The divider can be connected to the modules by means of coaxial cables and the modules can be connected to the radial combiner by means of microstrip to waveguide transitions.

Abstract: A hollow cylinder that has a permittivity greater than the permittivity of air is coaxially disposed within a waveguide with the proximal end of the cylinder coplanar with one end of the waveguide. The cylinder has a metal clad surface wherein a plurality of tapered slots that are narrowest at the proximal end of the cylinder and widest at the distal end thereof. The slots are coupled to respective amplification devices, thereby causing the waveguide to be terminated in an impedance substantially equal to impedances of the devices connected in series. Microwave power is transmitted through the waveguide via propagation of a wave in the TE.sub.01 mode. When the wave propagates to the cylinder, the power is transmitted to the devices via the electric fields within the slots at the proximal end of the cylinder. The wave propagates from the cylinder in response to the power being provided by the devices.

Abstract: A device which provides for uniform driving of a series of microwave trantors connected in parallel in a transistor pellet by utilizing a series of parallel microwave transmission lines of differing widths said widths being selected so as to compensate for the unequal effect of mutual inductance among the bond wires connecting said microwave transmission lines to the transistor pellet.

Abstract: A linear amplifier for an amplitude modulated RF input signal wherein the DC output-port bias voltage is varied in accordance with the current into the DC output-port to prevent amplitude and phase distortion of the output signal. Amplifiers utilizing bipolar and field effect transistors are disclosed.

Abstract: A linear high power transistor amplifier operable over a wide band of modulation frequencies wherein linearity of response is maintained by use of an active bias circuit.