SU1688310A1 - Band-elimination filter - Google Patents

Abstract

This invention relates to frequency separation devices. The aim of the invention is to expand the barrier line. The band-rejection filter contains a dielectric substrate 1, on the bottom surface of which a metal base (MO) is made, and on the top a strip conductor 3, to which a quarter-wave strip cable (4) 4, open at the end, is connected in parallel to MO. PS) intersects with the strip conductor 3, one end of which is located under the MSP 4 symmetrically with respect to its edges, and its other end is connected to a high-resistance reactive load. The high-frequency signal propagates along the transmission line formed by the strip conductor 3 and MO. At the point of connection of the PNSS 4 to the strip conductor 3 at the frequency fo, a short circuit of the transmission line is formed and the signal is fully reflected. Symmetrically with respect to this frequency, there are two additional frequencies with full reflection of the signal, which is achieved due to the interaction of the waves reflected from quarter-wave strip cable 4 and PSH. In this way, the expansion of the barrier band is ensured. 2 Il. w Ё

Description

The invention relates to the field of radio engineering, in particular, to devices for frequency separation of signals.

The aim of the invention is to expand the barrier line.

FIG. 1 shows the proposed filter, top view; in fig. 2 - the same, bottom view.

The band-rejection filter contains a dielectric substrate 1, on the bottom surface of which a metal base 2 is made, and on the top - a strip conductor 3, to which a quarter-wave strip cable 4 connected at the end is connected in parallel. A half-wave slot 5 is made in the metal base 2, crossing with the strip conductor 3, one end of which is located under the quarter-wave strip loop 4 symmetrically with respect to its edges, and the other end is connected to a high-resistance reactive load 6.

Band-stop filter works as follows. The high-frequency signal propagates along the transmission line formed by the strip conductor 3 and the metal base 2. At the point where the quarter-wave strip 4 is connected to the strip conductor 3, at the frequency f0 a short circuit of the transmission line is formed and the signal fully reflects the 00 00

with

about

with . Symmetrically with respect to this frequency, there are two additional frequencies with full reflection of the signal, which is achieved by the interaction of waves reflected from the reactivities created by the quarter-wave stripline 4 and half-wavelength gap 5. For the three attenuation poles,

y .., y 4 .y, Yn (tg26b + .1)

Sch 4 () yn YlU 4 ()

where Yn, Cond-conductivity of a quarter-wave strip loop 4 and half-wave gap 5, respectively;

f a Vc -

i TO

03

7Tf3

Tv

fo. f3 frequency of extinction poles; fc is the zero decay frequency. Connecting a half-wave gap to a high impedance load b provides for dan0

five

0

at its end idle mode. Thus, the introduction of the half-wave gap 5 provides three damping poles and expansion of the barrier line.

Claims (1)

Claims A band-reject filter containing a dielectric substrate, on the bottom surface of which a metal base is made, and on the top surface a strip conductor, to which a quarter-wave strip cable, open at the end, is different in that, in order to expand the barrier band, a metal base is made of a half-wave slit, crossing with a strip conductor, one end of which is located under a quarter-wave strip loop symmetrically relative to on its edges, and the other end connected to a high-resistance reactive load. Fig. / FIG. 2