V. D. Kotov

Synchronization and combining of the radiation powers of active microwave antennas integrated with field-effect transistors

Combining of the powers of microwave generators designed as a array of log-periodic antennas on a dielectric substrate and field-effect transistors as active components is experimentally investigated. Possibilities of a substantial increase in the generation efficiency due to mutual synchronization of radiators are demonstrated, and conditions for formation of the radiation pattern are studied.

Generation of microwave oscillations in a log-periodic antenna integrated with a field-effect transistor

Generation of microwave oscillations in a hybrid integrated circuit comprising a field-effect transistor and a log-periodic microstrip antenna on a dielectric substrate is experimentally investigated. Generation is observed at both the fundamental harmonic and higher frequencies corresponding to the antenna resonances in the frequency band 6–60 GHz. Possibilities of optimizing the generator design are studied in application to operation in centimeter and millimeter wave bands.

Generation of microwave radiation by active antennas with field-effect transistors in a quasi-optical resonator

Effects of locking of generator antennas (GAs) with field-effect transistors by the electromagnetic field formed as a result of reflection of radiation from a semitransparent dielectric mirror are analyzed. The possibility of spatial combining of the radiation powers of the GAs placed on a common dielectric substrate and forming a linear or a 2D matrix is demonstrated. It is shown that application of a reflecting mirror can substantially expand the GA mutual locking band and abandon external locking for power combining in the 2D matrix.

Generation of microwave radiation by active antennas with field-effect transistors locked by an external signal

Effects of locking by an external electromagnetic field of an array of oscillator antennas (OAs) designed by field-effect transistors integrated with log-periodic antennas are analyzed. The possibility of spatial combining of the radiation powers of OAs placed on a common dielectric substrate and arranged into a 1D array is demonstrated. It is shown that application of external locking can ensure severalfold broadening of the locking band of an ensemble of independent self-oscillators as compared to the case of mutual locking by a common field propagating in the dielectric substrate.

Active log-periodic antennas for spatial and quasi-optical microwave power combining

Power combining in the array of microwave oscillators, consisted of log-periodical antennas with field-effect transistors as active elements, is experimentally studied. The opportunity for considerable improvement of oscillation efficiency due to the mutual synchronization is shown and conditions of formation of the radiation pattern are defined.

Microwave oscillations in log-periodic antenna integrated with a field-effect transistor

Microwave oscillations in the hybrid integrated circuit consisted of field-effect transistor and microstrip log-periodical antenna is experimentally studied. The oscillations were observed both at the basic resonant frequency of the antenna and at the harmonics from 6 GHz to 60 GHz. The opportunities for set-up optimization were studied in application to millimeter wave frequency region.