複合形セラミック・トランス・フィルタ

抄録

Ceramic Transformer (CT) developed by C. A. Rosen has been applied as a transformer of high voltage-step-up ratio. However, this type CT has the demerit that the output voltage varies widely with a variation of circumference temperature and self-heating. This paper deals with the construction and the application of a band-pass-type Ceramic Trans-Filter (CTF) for the purpose of improving the demerits of the Rosen type CT. Four groups of CTF are described ; i. e. , the first group, types A and A', are constructed of two resonators using only a piezoelectrically unstiffened longitudinal vibration mode (see Figs. 1〜3). The second group, types B and B', are constructed from resonators designed by the Norton-transform method (Figs. 4, 5). The third group, types C and C' are constructed of two resonators using a piezoelectrically unstiffened and stiffened longitudinal mode (Figs. 6〜8). The last group, type D, is a differential-connection-type CTF constructed from two Rosen type CTs (Figs, 9, 10). Fig. 11 shows the synthetical comparison of the various type CTFs. It is evident that type C' is a useful composition because of its large transformation ratio n and large variable range of specific band width B. Type D is also a useful composition because of its stable construction. Figs. 13 and 14 present the experimental results of voltage ratio G_V for the modified C' type CTF (i. e. , C'_N type) transformed by the Norton-transform method and type D. It is apparent that these two CTFs act as more stable transformers at the center frequency. Table 2 shows a comparison between these two CTFs (i. e. , types C'_N and D) and the Rosen type CT. From this comparison, it is concluded that the former are better than the latter type on the basis of high voltage-stability for frequency shift by temperature variation.