Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements

HELECTRICITY H03Electronic circuits H03FAMPLIFIERS

H03F1/00Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements

H03F1/02Modifications of amplifiers to raise the efficiency H03F1/0205in transistor amplifiers H03F1/0211with control of the supply voltage or current H03F1/0216Continuous control H03F1/0222by using a signal derived from the input signal H03F1/0227using supply converters H03F1/0233by using a signal derived from the output signal H03F1/0238using supply converters H03F1/0244Stepped control H03F1/025by using a signal derived from the input signal H03F1/0255by using a signal derived from the output signal H03F1/0261with control of the polarisation voltage or current H03F1/0266by using a signal derived from the input signal H03F1/0272by using a signal derived from the output signal H03F1/0277Selecting one or more amplifiers from a plurality of amplifiers H03F1/0283Reducing the number of Dc-current paths H03F1/0288using a main and one or several auxiliary peaking amplifiers whereby the load is connected to the main amplifier using an impedance inverter H03F1/0294using vector summing of two or more constant amplitude phase-modulated signals H03F1/04in discharge-tube amplifiers H03F1/06to raise the efficiency of amplifying modulated radio frequency waves to raise the efficiency of amplifiers acting also as modulators H03F1/07Doherty-type amplifiers H03F1/08Modification of amplifiers to reduce detrimental influences of internal impedances of amplifying elements H03F1/083in transistor amplifiers H03F1/086with FET's H03F1/10by use of amplifying elements with multiple electrode connections H03F1/12by use of attenuating means H03F1/13in discharge tube amplifiers H03F1/14by use of neutralising means H03F1/16in discharge tube amplifiers H03F1/18by use of distributed coupling H03F1/20in discharge-tube amplifiers H03F1/22by use of cascode coupling H03F1/223with MOSFET's H03F1/226with junction-FET's H03F1/24in discharge-tube amplifiers H03F1/26Modifications of amplifiers to reduce influence of noise generated by amplifying elements H03F1/28in discharge-tube amplifiers H03F1/30Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters H03F1/301in MOSFET amplifiers H03F1/302in bipolar transistor amplifiers H03F1/303using a switching device H03F1/304and using digital means H03F1/305in case of switching on or off of a power supply H03F1/306in junction-FET amplifiers H03F1/307in push-pull amplifiers H03F1/308using MOSFET H03F1/309using junction-FET H03F1/32Modifications of amplifiers to reduce non-linear distortion H03F1/3205in field-effect transistor amplifiers H03F1/3211in differential amplifiers H03F1/3217in single ended push-pull amplifiers H03F1/3223using feed-forward H03F1/3229using a loop for error extraction and another loop for error subtraction H03F1/3235using a pilot signal H03F1/3241using predistortion circuits H03F1/3247using feedback acting on predistortion circuits H03F1/3252using multiple parallel paths between input and output H03F1/3258based on polynomial terms H03F1/3264in audio amplifiers H03F1/327to emulate discharge tube amplifier characteristics H03F1/3276using the nonlinearity inherent to components H03F1/3282Acting on the phase and the amplitude of the input signal H03F1/3288to compensate phase shift as a function of the amplitude H03F1/3294Acting on the real and imaginary components of the input signal H03F1/33in discharge-tube amplifiers H03F1/34Negative-feedback-circuit arrangements with or without positive feedback H03F1/342in field-effect transistor amplifiers H03F1/345using hybrid or directional couplers H03F1/347using transformers H03F1/36in discharge-tube amplifiers H03F1/38Positive-feedback circuit arrangements without negative feedback H03F1/40in discharge-tube amplifiers H03F1/42Modifications of amplifiers to extend the bandwidth H03F1/48of aperiodic amplifiers H03F1/483with field-effect transistors H03F1/486with IC amplifier blocks H03F1/50with tubes only H03F1/52Circuit arrangements for protecting such amplifiers H03F1/523for amplifiers using field-effect devices H03F1/526protecting by using redundant amplifiers H03F1/54with tubes only H03F1/542Replacing by standby devices H03F1/544Protection of filaments H03F1/546Delaying application of anode power supply with respect to application of filament heating power supply H03F1/548Protection of anode or grid circuit against overload H03F1/56Modifications of input or output impedances, not otherwise provided for H03F1/565using inductive elements