The impact of high-voltage-high-frequency (HVHF) amplifiers on echo-signal quality is greater with very-high-frequency (VHF, ≥100 MHz) ultrasound transducers than with low-frequency (LF, ≤15 MHz) ultrasound transducers. Hence, the bias voltage of an HVHF amplifier must be stabilized to ensure stable echo-signal amplitudes. We propose a bias-voltage stabilizer circuit to maintain stable DC volta...

A VHF (30MHz-300MHz) band digitally programmable low noise amplifier (LNA) has been implemented with a 0.25um standard CMOS process for VHF CMMB mobile TV tuners. Utilizing a T-match input network, input matching of more than a decade bandwidth is achieved across all gain settings. Adopting the multiple gated technique, gain flatness enhancement and capacitor reuse etc., the proposed LNA demons...

In this paper, very high frequency (VHF) current and voltage biquadratic lowpass filters implemented directly by the linear wideband finite-gain current and voltage amplifiers, respectively, are proposed and analyzed. A new Q-enhancement circuit which consists of a finite-gain wideband tunable voltage amplifier and a Miller capacitor is also proposed. It can increase the maximum-gain frequency ...

The coaxial transformer-coupled push-pull circuitry has been used widely in HF and VHF amplifiers for many decades without significant changes in the topology of the transformers. Basic changes over the years concerned the construction and turns ratio of the transformers as has been imposed upon the newer technologies active devices demands. The balun transmission line transformers applied in p...

Absfracr-The class E tuned power amplifier consists of a load network and a single transistor that is operated as a switch at tbe carrier frequency of tbe output signal. ‘zbe most simple type of load network consists of a capacitor shunting tbe transistor and a series-tuned output circuit, which may bave a residual reactance. Circuit operation is determined by tbe transistor when it is on, and ...

Skewing of the sex ratio towards males occurs among pups born to mice fed a very high saturated fat (VHF) diet. In the present study, we tested whether the fat content of the VHF diet rather than the number of calories consumed is responsible for this effect. Eight-week-old NIH Swiss mice were placed on the VHF diet either ad libitum (VHF) or in a restricted manner (VHF-R). The VHF-R mice gaine...

With increased saturation of the VHF band II used for FM, few frequencies are available for new radio stations in many markets. This paper describes the benefits of using the In Band On Channel (IBOC) signal in an all-digital configuration to boost the number of effective audio services in the FM band. A new method of creating an all-digital IBOC signal configuration is described. Multiple inst...