摘要:
A multi-channel, dual-band, radio frequency (RF) transmit/receive (T/R) module, for an active electronically scanned array, is provided. The module includes a compact, RF manifold connector and at least four T/R channels. Each of the T/R channels includes a notch radiator, a diplexer coupled to the notch radiator, a power amplifier, including at least one dual-band gain stage, coupled to the notch radiator, a low noise amplifier, including at least one lower-band gain stage and at least one upper-band gain stage, coupled to the diplexer, and a T/R cell, including a phase shifter, a signal attenuator and at least one dual-band gain stage, coupled to the power amplifier, the low noise amplifier and the manifold connector.
摘要:
An improved distributed amplifier usable, for example, in the gigahertz frequency range for radar and electronic warfare applications is disclosed. In the amplifier stage a combination of optimum amplifier stage loading, a reflection cancelling output network, and an amplifier capacitance hiding input arrangement are employed. The disclosure includes specific component values for one embodiment of the invention.
摘要:
A double balanced mixer consisting of an RF balun, a local oscillator balun and a diode “quad” bridge circuit connected between the two baluns and where the IF output is taken at the center tap of the RF balun secondary transformer. A second harmonic termination consisting of an RLC resonant circuit is coupled across the diode bridge at the RF side. Each arm of the diode bridge, moreover, includes three series connected diodes. The mixer is in the form of a microminiature integrated circuit (MMIC) using HBT emitter-based junction diodes fabricated on a gallium arsenide (GaAs) substrate.
摘要:
A plurality of heterojunction bipolar transistors (HBTs), each including one or more HBT cells, are combined so as to drive all of the cells equally and involves coupling the input drive signal via a pair of microstrip transmission lines to the two farthest transistors having a first common circuit node therebetween. A third microstrip transmission line is located between the other two microstrip transmission lines and is connected from the first circuit node to a second circuit node which is common to the two nearer transistors in order to couple the drive signal in an opposite direction to the nearer transistors. In such an arrangement, a negative mutual inductance exists between the center transmission line and the two outer transmission lines. The microstrip transmission lines are designed with physical dimensions and mutual separation distances so that the total inductance of the transmission lines which exists between the circuit nodes equals the mutual inductance be therebetween. The resulting net inductance will be zero and accordingly all four heterojunction bipolar transistors will be driven with signals applied to the respective bases which are equal in magnitude and in phase.
摘要:
A silicon microwave monolothic integrated circuit device and method of fabricating having a high resistivity silicon substrate with a masking layer of low temperature silicon oxide, silicon nitride and polysilicon sublayers on a first area, and an epitaxial layer over the surface of the silicon substrate in a second area. The active devices are formed over the second area and the passive devices are formed over the first area.
摘要:
A mixer having a diode quad, and which receives two RF signals at an RF input balun having primary and secondary windings. A resonant circuit arrangement includes at least a capacitor circuit element in parallel with the secondary winding to form an open circuit termination for the second harmonics of the input RF signals.
摘要:
A thermally stabilized cascode heterojunction bipolar transistor (TSC-HB) having the current and power generation regions in separate temperature zones, each transistor collector in a cold zone connected directly and individually to an emitter terminal of a corresponding transistor in a hot zone, thereby limiting the current available to the emitter of the transistor in the hot zone. Such an interconnection of transistors prevents the transistor in the hot zone from drawing more current from other transistor sources when increases in temperature occur. This achieves thermal stability and prevents the transistors from overheating and burning out.