Abstract: A broadband, high-speed RF step attenuator implemented using long-lifetime PIN diode switches is presented which provides step attenuation across a significant portion of the entire RF frequency spectrum while maintaining minimal insertion loss, return loss, and harmonics.

Abstract: A frequency synthesizer and method for synthesizing decimal frequencies. The synthesizer includes a seed generator, a clock synthesizer and an output synthesizer. The clock synthesizer includes a binary accumulator in a feedback signal path using a base reference frequency and a clock seed word for synthesizing a clock frequency and the output synthesizer includes a binary accumulator in a forward signal path using the clock frequency and an output seed word for synthesizing an output frequency. The output frequency is synthesized in decimal frequency steps from a decimal base reference frequency. Several output synthesizers may be driven in parallel from the same clock frequency for synthesizing several output frequencies in parallel.

Abstract: A frequency synthesizer and a method using a first seed word and a variable clock rate derived from a second seed word for synthesizing a signal frequency. An accumulator accumulates the first seed word at the variable clock rate with a remainder word for updating a reference word at the variable clock rate. The reference word has a most significant bit (MSB) and less significant bits (LSB)s. The remainder word corresponds to the LSBs at overflows of the MSB. A tracking filter filters the MSB for providing a filtered output signal having an output frequency derived from the first seed word and the variable clock rate. The variable clock rate is derived by direct synthesis from the second seed word and single sideband frequency upconversion. The tracking filter can be a phase lock loop with frequency upconversion.

Abstract: A frequency synthesizer and a method for synthesizing a microwave output signal frequency. The synthesizer uses a reference signal having a variable frequency and accumulation in feedback of a phase locked loop for synthesizing a microwave output frequency. The feedback accumulation rate is derived from a first seed word and the variable reference frequency is derived from a second seed word. A spur suppressor having arithmetic frequency conversions reduces the levels of in-band spurious signals of the variable reference frequency signal in order to reduce the spurious signal levels in the output signal.

Abstract: In a controlled signal generator or specifically a microwave frequency signal generator, which requires a quieting capacitor, improved switching speed without degrading noise performance is provided by switching out the quieting capacitor during frequency changes, precharging it to the new condition, and then reconnecting it for normal operation. Other error causing current drains are also compensated for.