US4450584A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave integrated circuit mixer
Assignee: Panasonic Holdings Corp
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Filing: 1982-06-25
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Granted: 1984-05-22
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Expires: 2002-06-25
Abstract
Abstract In a mixer using a planar circuit such as a strip line or a microstrip line etc., an IF signal interruption circuit which passes an RF signal but exhibits an open-circuit impedance against an IF signal is provided in shunt with a main line on which the RF signal propagates toward a mixer diode, and a low-pass filter 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
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:53
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
156 words
A single-ended microwave integrated circuit stripline or microstrip mixer, comprising a main line which connects an RF signal input terminal to one end of a mixer diode to transmit an RF signal to said mixer diode; means for applying an LO signal to said mixer diode; a first low-pass filter 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 provided in the RF signal path said main line and to pass said RF signal and provide an open-circuit impedance against said IF signal; and a second low-pass filter connected to said main line in the vicinity of said IF signal interruption circuit at a point distant from a mount point of said mixer diode to said main line for short-circuiting said IF siganl at said mount point.
Claim 2
Dependent Claim
156 words
A single-ended microwave integrated circuit stripline or microstrip mixer, comprising a main line which connects an RF signal input terminal to one end of a mixer diode to transmit an RF signal to said mixer diode; means for applying an LO signal to said mixer diode; a first low-pass filter 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 provided in the RF signal path said main line and to pass said RF signal and provide an open-circuit impedance against said IF signal; and a second low-pass filter connected to said main line in the vicinity of said IF signal interruption circuit at a point distant from a mount point of said mixer diode to said main line for short-circuiting said IF siganl at said mount point.
Claim 3
Dependent Claim
50 words
A microwave integrated circuit mixer according to claim 1, characterized in that said second low-pass filter 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
61 words
A microwave integrated circuit mixer according to claim 1, characterized in that said second low-pass filter 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
53 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 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
52 words
A microwave integrated circuit mixer according 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 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
79 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 is short-circuiting at the frequency of an image frequency signal, said further filter being constituted with a plurality of open-ended stubs connected in shunt with said main line 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
172 words
A microwave integrated circuit mixer according to claim 6, characterized in that said further filter is constituted with first, second and third open-ended stubs with a length of l 1 , l 2 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 l 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 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.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-22 | 1987-11-21 | 1988-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-22 | 1991-11-21 | 1992-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-22 | 1995-11-21 | 1996-05-22 | $7700.00 | Window Closed / Lapsed |