Reference [1] concluded that for the phase-locking of Gunn Oscillator, timing by varying the bias voltage on the diode is not a practical method. However the author of this paper successfully realized the 8mm (35 GHz) phase-locking standard fre-quency source and 8 mm fixed intermediate frequency phase-locking tracker with this method. This paper analyzes also the unique advantage of the new method. The ex-perimental results are given.

In this paper, a method of analysing the short backfire antenna is proposed. Using this method, a new type backfire antenna is developed. Its gain is about 2.5 dB higher than that of a normal short backfire antenna.

In this paper, the causes and the suppression methods of the overvoltages in silicon rectifiers are described. The selection methods of the metal oxide, varistors are described also. These suppression methods are also useful to other semiconductor devices.

VVMOS transistor is a new type of high frequency power MOS transistor with vertical channels at the surface of the V-groove. Like other MOSFET s, one of the important features is no secondary breakdown, However, these is negative resistance breakdown, effect in MOSFET's is reported recently by some authors. The reported effects may eause secondary breakdown, and result in destructive damage to the de-vices.While measuring the VVMOSFET s made in our laboratory, we have also observed the destructive negative resistance breakdown effect. And model based on the effect of parasitic vertical bipolar npn transistor is proposed to explain this effect. Some using these method, the negative resistance breakdown effect has been lowered of even eliminated, and thus the proposed negative resistance breakdown model for VVMOSFET's is verified.

In this paper, we propose a new eriterion and a method for designing filter type output circuit of broadband klystrons. From this, we ean obtain an output section which satisfies the requirement of klystron designs, and have good impedance-band-width characteristies. From equivalent circuit, we can directly calculate the gap in-teraction impedance, and obtain the effect of parameters of the output circuit on which the impedance-bandwidth characteristies depends. According to caleulated curves, we can get optimum results through adjusting the parameters of output circuit in the actual manufacture.

In this paper, the electrodynamic system, working principle and characteristics of a few different kinds of CRM-oscillators have been analyzed and compared. The analysis shows that two-resonant cavity synchronous CRM-oscillator with external signal and the two-resonant cavity CRM-oscillator with external back-coupling are ideal high power oscillators in the range of millimeter wave and submillimeter wave.

As a small spherical aberration eleetrostatic lens Septier s lens has been proved to be an almost ideal structure by a number of experiments. This paper provides a meth-od of calculating all the physical characteristics of Septier s electrostatic lens. It also provides the calculated results at various geometrie sizes and voltages; they are useful for making correct choice under different conditions.

Pulse emission current at the inflection point on I-U curve of a thermionie eathode can be measured rapidly by means of a circuital technique. This method can prevent the eathode from suffering injury during the measurement. So that it can be used to compare the emission levels between different thermionie cathodes, and to monitor the changes of activation of cathodes during life test. The principle of the rapid-measurement of pulse emission current at the inflection point on I-U curve of the thermionic caathode is discribed. Autodisplay of the inflection point on the I-U characteristics is realized. The method of verification of its correctness is given. A great deal of measurements on various thermionic cathodes show that the instrument is of practical value. Finally the measuring error of the instrument is discussed.

A new empirical formula for calculating the T_c, of A-15 supereonductors is presented and it reads: T_c=N T_A/M^1/2(r_A/r_B) (e/a), where N——number of atoms,N = 4 for A₃B compounds; T_A ——the superconductive transition temperature of the A element; M——the. average atomic weight of the compounds; (r_A/r_B) ——theatomic radius ratio of elements A and B; (e/a) —— the eleetron concentration (electrens/atoms). Using the new empirical formula, the supereonductive transition temperatures of A-15 compounds have been calculated, and the results are shown in table  1. As shown in the table the calculated results are much closer to the experimental results than those obtained by other empirical formulas. The highest T_c value of A-15 structural materials may be not higher than 25K.

In this paper, a eircular-circular pillbox type sapphire window used in circullar waveguide transmitting system which consists of 8 mm band gyrotron oscillator is described.