V. A. Kozlov – Dr.Sc. (Eng.), Professor, Head of Department, FSUE FRPC “Measuring System Research Institute n.a. Yu.Ye. Sedakov” (Nizhny Novgorod). E-mail: vKozlov@niiis.nnov.ru
A. L. Kunilov – Leading Research Engineer, FSUE FRPC “Measuring System Research Institute n.a. Yu.Ye. Sedakov” (Nizhny Novgorod)
M. M. Ivoylova – Post-graduate Student, Research Engineer, FSUE FRPC “Measuring System Research Institute n.a. Yu.Ye. Sedakov” (Nizhny Novgorod)
When designing onboard microwave radio devices which output spectrum contains harmonics of the main signal (oscillators, frequency multipliers, power amplifiers, frequency synthesizers), the problem of filtering of the main signal of frequency f 0 arises, which is typically solved by using band-pass filters (BPF) or low-pass filters (LPF). Use of BPFs is preferred in certain cases, as it allows to exclude not only harmonics of the main frequency nf 0 (n > 1), but also overtone frequencies and harmonics of comparison frequencies of synthesizers. One of promising types of microwave BPFs is filters based on quarter wavelength coaxial ceramic resonators (CCR). However, using CCR-based BPFs poses the problem of attenuation of the main signal odd harmonics (2n + 1)f 0, which are caused by the existence of equidistant fundamental frequencies of quarter wavelength resonators.
The article presents an oscillatory system in the form of a composite coaxial ceramic resonator (CCCR), which fundamental frequencies have non-equidistant location on the frequency axis. Mechanically, the CCCR consists of two segments of coaxial lines of ceramic materials with different permittivity, with same diameters of inner and outer conductors, one of which is short-circuited at one end, connected to each other at their opens ends, and with their inner and outer conductors bonded galvanically. The electrodynamic model of CCCR has been developed, the critical frequencies of higher type oscillations for TE-waves and TM-waves have been determined from the equations obtained by using the partial domains method. The analytical expressions for CCCR impedance, fundamental frequencies and quality factor have been shown. It has been also demonstrated that the maximum deviation of the second resonant frequency of a CCCR from 3f 0 is achieved when electrical lengths of the two coaxial line segments are equal.
There are also shown the results of experimental studies of CCCR samples made of TL/0 (ε = 40), V100 (ε = 100) ceramics and studies of a control sample of CCR made of V100 ceramics, as well as parameters of dual resonator BPF designed on the basis of the above samples.
i funkcionalnye uzly SVCH- i KVCH-diapazonov. Metody rascheta i tekhnologija
izgotovlenija / pod. red. Sedakova A.JU.M.: Radiotekhnika. 2011.