Abstract:
A multiple-frequency local oscillator (200) for providing an LO signal at one of a multiple of predetermined resonant frequencies associated with a number of resonators (210). It includes a number of LO input ports (205) for coupling to the plurality of resonators (210). The local oscillator is controlled to selectively provide at its LO output port (215) an output LO signal at any one of the resonant frequencies.
Abstract:
An automatic transimpedance control amplifier (100) is disclosed. The amplifier incorporates an automatic gain circuit (155) which simultaneously and automatically adjusts the value of the transimpedance and the voltage gain at each gain stage of the amplifier (115, 130) according to the input current. The amplifier has wide bandwidth, high sensitivity, and more importantly, wide dynamic range.
Abstract:
A new type of field effect transistors, bootstrapped gate field effect transistors ("BGFETs") for providing variable resistance is disclosed. A BGFET includes source (420), drain (425), gate (430), and channel regions (405). The gate region consists of resistive material and it provides with respect to the channel region distributed resistance and capacitance which imposes distributed feedback to the gate region of AC signal applied to the source or drain regions. BGFETs can be further externally bootstrapped to reduce the lower frequency limit at which it can properly operate.
Abstract:
The present invention provides a power amplifier operating with a signal power supply. The amplifier includes at least one depletion-mode FET (110) for amplifying an ac signal and a negative voltage generator (107) for providing a bias to the FET (110). The generator (107) includes a multivibrator (115) for producing two clock signals and a charge pump (120) which receives the clock signals and produces a negative voltage. Advantageously the negative voltage is provided as a low reference potential to the multivibrator (115) so that the clock signals it produced include a negative voltage period, which enables the charge pump (120) to operate in a power efficient manner.
Abstract:
A plastic package for microwave applications up to 14 Ghz is disclosed. The plastic package includes a plastic platform (65), a lead frame embedded on the surface of the platform (65) and, in one embodiment, a plastic cap (75) mounted on the platform (65) so as to seal the chip (70) within the package. The lead frame includes a baseplate (71) for mounting at least one semiconductor chip (70), at least one ground lead attached to the baseplate (71) and extending outwardly therefrom, and at least one signal lead for conducting signals to or from such semiconductor chip (70). The signal lead and at least one ground lead are configured as a microwave transmission line such as microwave coplanar strips, or microwave coplanar waveguide for transmitting microwave frequency signals. The package offers a low inductance ground path, good thermal characteristics, and low parasitic inductance and capacitance. It can be applied for high speed and high frequency applications.