SU1234896A1 - Tuneable microwave circuit - Google Patents

Abstract

The invention relates to engineering. Microwave The frequency tuning range of the 1st overtone is extended. The contour contains a segment of the coaxial line (GST) 1, the outer and inner conductors 2 and 3 of which are respectively short-circuited at one end by the plate 4, and at the other end loaded with a capacitor 5. The GFR1 is connected in parallel with the open-cut segment of the coaxial line (ROCK) 6, the characteristic impedance (BC) which is less than the wave resistance of the GST 1 (BC |). There is an optimal place to turn on the ROKL 6 hoot 2/3. When BC decreases, opt its optimal length decreases, and the frequency tuning range of the 1st overtone expands. Work on the 1st overtone is characterized by higher Q-factor. 1 hp f-ly. 1 il. 00 4 00 O5

Description

"

. The invention relates to microwave technology and can be used as a tunable resonant circuit of generators or amplifiers.

The purpose of the invention is the expansion of the frequency range of the first overtone.

, The drawing shows a diagram of the tunable microwave circuit.

The tunable microwave circuit contains a segment 1 of the coaxial line, the outer and inner conductors 2 and of which, respectively, are short-circuited at one end of the plate 1, and at the other end are loaded, with a variable capacitor 5. To segment 1 of the coaxial line is connected in parallel to the open section 6 of the coaxial line, the characteristic impedance of which is less than the characteristic impedance of the segment 1 of the coaxial

lines.

one

 The tunable microwave circuit can be represented as a reactive circuit with an input resistance X (co) and a capacitor 5 of variable capacitor C „

Resonant frequency s;

I)

i 1, 2,

.0., Completely dependent on these elements:

one

SOS

- X (with)

(one)

The range of variation of the resonance frequency; characterized by frequency overlap ratio

TO; with;

de; ..

/ CO;

vnay (1 min 7

- the maximum value of the frequency, corresponding to; its minimum value of the variable capacitance of the capacitor 5,

X (m) W

 - ctg i-ul - tg (oj - ctg | - (oE mtg- | co - ctg-J-co + tg | -coT tg - Co ctg wl

m W / W - relative wave resistance pa of the closed segment 6 of the coaxial line ni / relative length of the open segment 6 of the coaxial line;

 - - t and minimum value

frequency corresponding to the maximum value of the variable capacitor capacitance 5.

Bandwidth at the resonant frequency; will be higher if, at a given change in the variable capacitance of the capacitor 5, a higher. K value is reached; In turn, the value of K; depends on the relative width of the resonance region K;

h npoi,

to

: -tOn

 pre f

 W.

(2)

where Wp; and yd; respectively, the pole and zero of the input resistance X (and) at the connection points of the variable capacitor 5. The greater the value of K y) prr) those. more than the value of the frequency overlap factor K (will be achieved with the previous change in the capacitor 5 capacitance. In the private case, when the variable capacitance C changes from zero to infinity, the equality K, –K is satisfied; before;

For a tunable microwave circuit containing segment 1 coaxial

L - Lines of length f with a characteristic impedance W, the input resistance X (w) is equal to

X (s) W tg (r,

(3)

where V is the propagation velocity

electromagnetic wave. If to the segment 1 of the coaxial line is connected in parallel at a distance of 2 (from the plate 4 an open section .6 of the coaxial line of length V and wave impedance W, then the input resistance at the connection points of the variable capacitor 5 will change

(four)

h 1, / 1 is relative to the inclusion coordinate of the open segment 6, coaxial, or 557 LII.

Equating the numerator and denominator (4) to zero, we obtain the transcendental equations defining the zeros and the field.

sy functions X (hell). From expressions (2) and (4) it follows that the value of K, “g depends on the relative parameters of the open segment 6 of the coaxial line.

The analysis showed that the extension of the frequency range of the first overtone occurs at ha 1, i.e. when the characteristic impedance W of an open segment 6 of a coaxial line is less than the characteristic impedance W of a segment 1 coaxial

NOI lines. I

The smaller the wave resistance (the larger the parameter m), the stronger the semi-positive effect that takes place at an arbitrary length, and the on-coordinate of the open segment 6 of the coaxial line.

There is an optimal place for the inclusion of an open segment 6 of the coaxial line h

Op-t

 2/3. With

decreasing the wave resistance of an open segment 6 (increasing the parameter ift) its optimal length

Editor Y. Sereda Order 2988/54

Compiled by N.Tkacheva

Tehred L.Oleynik Proofreader V.But ha

Circulation 597 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

the frequency of the first overtone expands. The operation on the first overtone is characterized by a higher Q.

Claims (2)

1. IlepecTpaHBaeMbrfi microwave circuit containing a segment of a coaxial line, the outer and inner conductors of which are short-circuited at one end and loaded with a variable capacitor at the other end, so that expansion of the frequency tuning range of the first overtone, the open section of the coaxial line is connected in parallel to the segment of the coaxial line, the characteristic impedance which is less than the wave resistance of the coaxial line segment, 2. The microwave circuit of claim 1, wherein the open section of the coaxial line is included at a distance equal to 2/3 of the length of the section of the coaxial line from its short-circuited end.