S. N. Artemenko

A study of the switching of the microwave compressor switch in a circular waveguide

Results of the experimental study of the interference switch for the H11 mode in a circular 10-cm-wavelength waveguide are presented. The conditions required for efficient microwave discharge switching of the interference switch are determined. The results of the study of the switching process allowed us to design and produce an interference switch with better characteristics than those of rectangular waveguides. It is shown that this switch extracts the stored energy from the microwave compressor cavity more efficiently and improves the amplitude stability of the output pulse radiation.

Note: Resonant microwave compressor with two output ports for synchronous energy extraction

The brief theoretical analysis shows the resonant microwave compressor provides the output pulse power higher than the traveling wave power in the storage cavity. The experimental study was made with the model of the S-band microwave compressor. The power of pulses generated by the device reached the value three times as much as the value of the traveling wave power in the storage cavity at the maximum amplification 23 dB, peak power 400 MW, and pulse width 4-5 ns.

A two-step system for compression of microwave pulses in series-coupled resonators

A system for resonance compression of microwave pulses consists of two resonators connected in series: the first is a high-Q oversized resonator and the second is a single-mode cylindrical resonator. The time dependences of the field strength in the resonators during their excitation and the energy transfer at different values of the transfer coefficient have been determined for the 10-cm wavelength region. The results of experimental studies are presented. The output pulses are 3 ns in length and have a maximum pulse power of 1.2 GW.

Development of High Power Microwave Compressors

Parameters of high power microwave compressors having a single storage cavity are presented for different frequency bands. Their resonant cavities operated with electrical field strength values close to critical ones which allowed par ex. to reach the output pulse power about 2 MW in Q- band and about 200 MW in S-band. Ways to go beyond these power values were considered. They were using asymmetrical TE-mode in a circular cavities, energy extraction through a multiport output element, the waveguide hybrid in this report, and series compression with resonant transfer of the energy stored in the first stage cavity.

Formation of pulses with controlled parameters in a resonance microwave compressor employing oscillation-mode transformation

Results of an experimental study of the formation of rf pulses with controlled power, duration, repetition rate, and envelope parameters in a resonance compressor employing oscillation-mode transformation are presented. The pulse parameters are varied by using tuned intermodal coupling elements. A possibility of the formation of a series of subsecond and nanosecond rf pulses in the partial extraction of energy and nanosecond pulses of various durations in single complete extraction of energy from the compressor resonator is shown.

Experimental investigation of a 25-MW microwave (3-cm range) compressor prototype

An experimental study of a resonance microwave (3-cm-range) compressor with gas insulation and energy output through a superdimensional coaxial interference switch is reported. The rated parameters of the compressor are output signal power ∼25 MW, signal duration 2 ns, gain 26 dB, and efficiency ∼57%. A gain of 20 dB was achieved at a peak output signal power of 12 MW, signal duration of 2 ns, efficiency of ∼24%, and traveling wave power of 24 MW.

Cryogenic resonant microwave compressors with energy extraction through “warm” interference switches

A method of switching cryogenic resonant microwavecompressors from the energy accumulation mode to the energy release mode is proposed and analyzed. The switching process is based on the resonant transfer of the microwaveenergy from a cryogenic storage cavity to a room temperature commutation cavity. The transfer can be realized using a cascade interference microwave switch weakly coupled to the storage cavity and consisting of two H-plane waveguide tees connected in series. The tees are made of a normally conducting material, located outside the cryostat, and contain commuting units in shorted side arms. The length of the cascade input arm (from the storage cavity to the first tee) is non-resonant, while the space between the storage cavity and the second tee is resonant. The weak coupling of the storage cavity to the cascade and the non-resonant length of its input arm allow one to minimize losses during the energy accumulation phase. When the commuting unit in the first tee is ignited, the tee opens, and the non-resonant volume of the cascade input arm is transformed into the volume of the resonant commutation cavity. The microwaveenergy is then transferred in a resonant way from the storage cavity to the commutation cavity, and when the transfer is complete, the commuting unit in the second tee is ignited to extract the energy into a load. It is shown analytically that, at a certain value of the coupling (the cryogenic storage cavity to the normally conducting cascade of tees) and length of the cascade input arm, the power gain in the storage cavity can be kept high. It is also shown that the energy accumulated in the storage cavity can be effectively transferred to the commutation cavity and from the commutation cavity to the load.

Microwave-energy extraction from a resonator via oversized interference switch

We have studied an interference switch based on an oversized H-plane rectangular waveguide T-junction. Conditions necessary for effective operation of the switch as an energy extractor are evaluated. Microwave pulses of 3.5-ns duration with 2.8-MW power at a gain of 17.5 dB have been obtained using a prototype microwave compressor for the 3-cm waveband with a 72 × 34 mm2 waveguide resonator and a 58 × 25 mm2 waveguide switch. It is shown that, using the proposed switch, it is possible to obtain RF pulses with a power of up to ∼0.1 GW in the 3-cm band and ∼1 GW in the 10-cm band.

Synchronous extraction of microwave energy from cavities through a packet of interference switches

Synchronous extraction of energy from cavity resonators for X-band microwave radiation through a compact packet of five interference switches based on H tees has been experimentally analyzed. It is shown that switches can be completely synchronized and the synchronization conditions are determined. Microwave pulses have been generated upon synchronous extraction of energy from five single-mode cavities (power ∼0.8 MW, gain ∼12 dB, and width ∼3.2 ns) and from one superdimensional cavity (power ∼2.2 MW, gain ∼16.5 dB, and width ∼3.5 ns). The operation limits of X- and S-band microwave compressors with extraction of energy through a packet are estimated.

Controlling output pulse and prepulse in a resonant microwave pulse compressor

A resonant microwave pulse compressor with a waveguide H-plane-tee-based energy extraction unit was studied in terms of its capability to produce output pulses that comprise a low-power long-duration (prepulse) and a high-power short-duration part. The application of such combined pulses with widely variable prepulse and high-power pulse power and energy ratios is of interest in the research area of electronic hardware vulnerability. The characteristics of output radiation pulses are controlled by the variation of the H-plane tee transition attenuation at the stage of microwave energy storage in the compressor cavity. Results of theoretical estimations of the parameters tuning range and experimental investigations of the prototype S-band compressor (1.5 MW, 12 ns output pulse; ∼13.2 dB gain) are presented. The achievable maximum in the prepulse power is found to be about half the power of the primary microwave source. It has been shown that the energy of the prepulse becomes comparable with that of the sh...