EP0068870A2
Expired / Lapsed
EP
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Microwave integrated circuit mixer
Assignee: Panasonic Holdings Corp
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Filing: 1982-06-28
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Granted: —
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Expires: 2002-06-28
Abstract
Abstract In a mixer using a planar circuit such as a strip line or a microstrip line etc., an IF signal interruption circuit (9, 27) which passes an RF signal but exhibits an open-circuit impedance against an IF signal is provided in shunt with a main line (2,21) on which the RF signal propagates toward a mixer diode (3, 22), and a low-pass filter (10, 11, 28) is connected in the vicinity of the IF signal interruption circuit in order to short-circuit a mount point of the diode for the IF signal by high frequency short-circuiting technique wherein an open-ended quarter wavelength transmission line or a short-circuited half-wavelength transmission line is used, whereby low noise performance can be obtained over a wide frequency band even under such an operating condition that the IF signal is in the GHz band.
Inventors
- 👤 Hiroshi Saka
- 👤 Toshihide Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 15:07
CPC Classifications
H; H03; H03D; H03D9/00; H03D9/06; H03D9/0608; H03D9/0633; H03D2200/00; H03D2200/0001; H03D2200/0037
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
165 words
A single-ended mixer using a microwave integrated circuit with a strip line or a microstrip line as a basic constitution, comprising a main line (2) which connects an RF signal input terminal (1) to one end of a mixer-diode (3) to transmit an RF signal to said mixer diode; means (5) for applying an LO signal to said mixer-. diode; a first low-pass filter (6) connected to the other end of said mixer-diode for taking out an IF signal with a frequency equal to the difference between the frequencies of said RF signal and said LO signal; an IF signal interruption circuit (9) which is provided on said main line and passes said RF signal while exhibits an open-circuit impedance against said IF signal; and a second low-pass filter (10) which is connected to said main line on the side of said mixer diode in the vicinity of said IF signal interruption circuit to short-circuit a mount point of said mixer-diode for said IF signal.
Claim 2
Dependent Claim
165 words
A single-ended mixer using a microwave integrated circuit with a strip line or a microstrip line as a basic constitution, comprising a main line (2) which connects an RF signal input terminal (1) to one end of a mixer-diode (3) to transmit an RF signal to said mixer diode; means (5) for applying an LO signal to said mixer-. diode; a first low-pass filter (6) connected to the other end of said mixer-diode for taking out an IF signal with a frequency equal to the difference between the frequencies of said RF signal and said LO signal; an IF signal interruption circuit (9) which is provided on said main line and passes said RF signal while exhibits an open-circuit impedance against said IF signal; and a second low-pass filter (10) which is connected to said main line on the side of said mixer diode in the vicinity of said IF signal interruption circuit to short-circuit a mount point of said mixer-diode for said IF signal.
Claim 3
Dependent Claim
51 words
A microwave integrated circuit mixer according to Claim 1, characterized in that said second low-pass filter (10) has an open-ended structure, and the line length between said mixer diode and the open end of said second low-pass filter is selected to be equal to the 1/4 wavelength of said IF signal.
Claim 4
Dependent Claim
62 words
A microwave integrated circuit mixer according to Claim 1, characterized in that said second low-pass filter (11) has such a structure that its end terminal is short-circuited to a ground and that the line length between said mixer diode and said short-circuited end terminal of said second low-pass filter is selected to be equal to the 1/2 wavelength of said IF signal.
Claim 5
Dependent Claim
55 words
A microwave integrated circuit mixer according to Claim 1, characterized in that said IF signal interruption circuit is constituted with an interdigital-type direct current block (Fig. 4a) where two open-ended strip-lines are parallel-coupled over a length nearly equal to a 1/4 wavelength of said RF signal from the open end of said open-ended strip lines.
Claim 6
Dependent Claim
54 words
A microwave integrated circuit mixer acccrding to Claim 1, characterized in that said IF signal interruption circuit is constituted with a band-pass filter consisting of at least one half-wavelength strip-line resonator (Fig. 4b) where the length of said half-wavelength strip line resonator is selected to be equal to 1/2 wavelength of said RF signal.
Claim 7
Dependent Claim
82 words
A microwave integrated circuit mixer according to Claim 1, characterized in that a further filter is connected to said main line at a position where the impedance seen from said mixer-diode (22) is short-circuiting at the frequency of an image frequency signal, said further filter (23) being constituted with a plurality of open-ended stubs (23) connected in shunt with said main line (21) and exhibiting a stop-band against said image frequency signal while a pass-band at the frequency of said RF signal.
Claim 8
Dependent Claim
175 words
A microwave integrated circuit mixer according to Claim 6, characterized in that said further filter (23) is constituted with first, second and third open-ended stubs (Fig. 6) with a length of ℓ 1 , t2 and ℓ 3 respectively connected in shunt with said main line with an equal, or a nearly equal, spacing ℓ 0 , that the lengths ℓ 1 , ℓ 2 and ℓ 3 of said first, second and third open-ended stubs are selected to be equal to, or nearly equal to, the 1/4 wavelength of said image frequency signal such that the poles of attenuation lie within the band-width of said image frequency signal or in the vicinity of the band-width of said image frequency signal, and that lengths ℓ 0 , ℓ 1 , ℓ 2 and 1 3 are selected to satisfy a condition of ℓ 2 <ℓ 1 <ℓ 0 <2ℓ 2 and ℓ 2 <ℓ 3 <ℓ 0 <2ℓ 2 or a condition of ℓ 2 <ℓ 1 = ℓ 3 <ℓ 0 <2ℓ 2 .
Claim 9
Dependent Claim
45 words
A microwave integrated circuit mixer according to Claim 7, characterized in that the spacing ℓ 0 between said first, second and third open-ended stubs is selected to be longer than 5/16 wavelength of said RF signal but shorter than 7/16 wavelength of said RF signal.
Claim 10
Dependent Claim
78 words
A microwave integrated circuit mixer according to Claim 1, characterized in that an IF signal output matching circuit (26) is provided on the output side of said first low-pass filter, said IF signal output matching circuit is constituted with at least more than one inductive shunt element with its end short-circuited to a ground and at least one of said inductive shunt elements being used as a DC return circuit for the bias current flowing through said mixer-diode.
References Cited (Backward Citations)
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