A solid state high power microwave amplifier module. The module incorporates a stacked assembly of integrated low temperature cofired ceramic substrates forming a monolithic structure containing all the microwave circuitry required to combine the output power of a large number of monolithic microwave integrated circuit power amplifier chips, a heatsink and a power supply. One substrate defines an input radial power divider circuit for dividing the input signal into input signals for each power amplifier chip. The second substrate includes the power amplifier chips and a radial combiner circuit. The output of the combiner to coupled to an output waveguide in the heatsink. The module is lightweight and small in size, and of high reliability since the number of wire bonds is greatly reduced since most of the microwave circuitry and connections can be formed as part of the integrated structure.

A power combiner has been described incorporating N transmission lines each having a quarter wavelength or multiple thereof for a frequency within a predetermined frequency range where the input of each transmission line has a resistor coupled thereto with the other ends of the resistors coupled together using inductance and capacitance to compensate for the distances between the resistors to provide a floating node which is low impedance in the predetermined frequency range. A composite amplifier is described on gallium arsenide wherein a power divider and power combiner are coupled to a plurality of MESFET's and wherein each input and output of the power combiner and power divider have a resistive load with respect to the MESFET while including a matching circuit and wherein each input of the combiner has a resistor coupled to a first floating node and each output of the divider has a resistor coupled to a second floating node. The invention overcomes the problem of a composite amplifier where many elemental amplifiers must be driven and their output signals combined at frequencies where the physical layout would provide phase differences such as in a layout of parallel cells on a flat surface of a substrate.

A microwave power combiner/divider is matched internally and has increased bandwidth. A microwave integrated circuit disk within the housing has high impedance radially directed quarter-wavelength lines to obtain an impedance match for the desired mode at the centered coaxial port. Bridging half-wavelength lines between adjacent peripheral ports match the undesired mode and connect to absorbing resistors; these lines also provide bandwidth compensation. The housing has an annular shield with an opening near the centered coaxial line to provide a high choke impedance.

A divider/combiner amplifier circuit divides input power through a sectored coaxial line to a plurality of longitudinal parallel channels spaced around the circumference of a cylinder; the power in each channel is amplified by a semiconductor device; and the amplified power is combined in another sectored coaxial line. A microwave waveguide connected to the input and output of each amplifying device confines the microwave energy of the operating mode to the longitudinal channel formed by said waveguide. Each waveguide extends longitudinally along the cylinder and each is circumferentially spaced from its neighboring waveguide by a space which forms a cut-off waveguide to the operating mode. In the event of a failure of one or more amplifying elements, the space allows the failure mode to propagate radially to microwave absorbing material where it is absorbed to prevent reflection back into the longitudinal waveguide and thus effectively isolates the failure to provide a gradual deterioration of the amplifier circuit performance with element failure.

A divider/combiner amplifier circuit divides input power through a sectored coaxial line to a plurality of longitudinal parallel channels spaced around the circumference of a cylinder; the power in each channel is amplified by a semiconductor device; and the amplified power is combined in another sectored coaxial line. A microwave waveguide connected to the input and output of each amplifying device confines the microwave energy of the operating mode to the longitudinal channel formed by said waveguide. Each waveguide extends longitudinally along the cylinder and each is circumferentially spaced from its neighboring waveguide by a space which forms a cut-off waveguide to the operating mode. In the event of a failure of one or more amplifying elements, the space allows the failure mode to propagate radially to microwave absorbing material where it is absorbed to prevent reflection back into the longitudinal waveguide and thus effectively isolates the failure to provide a gradual deterioration of the amplifier circuit performance with element failure.