EP0346089A1
Expired / Lapsed
EP
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Reception system
Assignee: Nippon Sheet Glass Co Ltd
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Filing: 1989-06-07
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Granted: —
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Expires: 2009-06-07
Abstract
Abstract An inductance element (L₁) is arranged to parallel resonate with a ground stray capacitance component (C₂,C₃) of an antenna on a motor vehicle and a feeder cable (7) to a radio receiver tuner (21). Matching means (L₂) is provided to compensate for a Q-factor of the parallel resonance for improving a reception gain over a wide range in a reception band. The matching means may be a low pass filter (23). The parallel-resonance circuit inductance may be provided wholly by choke coils (11a, 11b) in power leads (12, 13) of a heater circuit in which the antenna (2) is formed by a plurality of heater wires on a vehicle window (1).
Inventors
- 👤 Kaoru C/O Nippon Sheet Glass Co. Ltd. Sakurai
- 👤 Harunori Nippon Sheet Glass Co. Ltd. Murakami
- 👤 Hiroshi Nippon Sheet Glass Co. Ltd. Iijima
- 👤 Masaru Nippon Sheet Glass Co. Ltd. Maeda
- 👤 Koji Nippon Sheet Glass Co. Ltd. Matsuda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 09:45
CPC Classifications
H; H03; H03H; H03H3/00; H01; H01Q; H01Q1/00; H01Q1/12; H01Q1/1271; H01Q1/1278
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
102 words
A reception system for a motor vehicle having an antenna circuit including an antenna element for supplying a reception signal to a receiver, characterized in that said system comprises: an inductance element (L₁, L₃) connecting the antenna circuit (2, 6, 7, 8) to ground and constituting a parallel resonant circuit together with a ground stray capacitance of said antenna circuit at a frequency set in a reception band; and matching means (L₂, TC) associated with said parallel resonant circuit to compensate for a Q-factor of the parallel resonance so that a reception gain is improved over a wide range of reception frequencies.
Claim 2
Dependent Claim
102 words
A reception system for a motor vehicle having an antenna circuit including an antenna element for supplying a reception signal to a receiver, characterized in that said system comprises: an inductance element (L₁, L₃) connecting the antenna circuit (2, 6, 7, 8) to ground and constituting a parallel resonant circuit together with a ground stray capacitance of said antenna circuit at a frequency set in a reception band; and matching means (L₂, TC) associated with said parallel resonant circuit to compensate for a Q-factor of the parallel resonance so that a reception gain is improved over a wide range of reception frequencies.
Claim 3
Dependent Claim
29 words
A reception system according to claim 1 characterized in that said matching means comprises an element (L₂, C₄, C f , T c ) being responsive to reception frequencies.
Claim 4
Dependent Claim
53 words
A reception system according to claim 1, characterized in that said inductance element comprises a first coil element (L₁) connecting said antenna circuit (2, 6, 7, 8) to ground, and said matching means comprises a second coil (L₂) element connected into a reception signal path of said antenna circuit (2, 6, 7, 8)
Claim 5
Dependent Claim
59 words
A reception system according to claim 3, characterized in that said matching means further comprises a capacitive element (C₄, C f ) connecting an end of said second coil element (L₂) on the side of said receiver (21) to ground, said matching means being a low-pass filter (23, 33) consisting of said second coil element and said capacitive element.
Claim 6
Dependent Claim
83 words
A reception system according to claim 4, characterized in that said antenna circuit comprises a feeder cable (7) which connects said antenna element (2) to said receiver, said first coil element (L₁) is connected to an end of said feeder cable on the side of said receiver and said second coil element (L₂) connects the end of said cable to an input of said receiver, and said capacitive element (C₄) is a capacitor (25) connecting said input of the receiver (21) to ground.
Claim 7
Dependent Claim
23 words
A reception system according to claim 5, characterized in that a damping resistor (R₁) is further coupled in parallel with said capacitor (25).
Claim 8
Dependent Claim
50 words
A recepetion system according to claim 3, characterized in that said parallel resonant circuit (26, 32) and said matching means (L₂, TC) operate effectively in an AM broadcast band and a capacitor (C₅) is parallel connected to said second coil element for (L₂) FM reception signal to bypass the coil.
Claim 9
Dependent Claim
81 words
A reception system according to claim 4, characterized in that said antenna circuit comprises a feeder cable (7) which connects said antenna element (2) to said receiver (21), said first coil element (L₁) is connected to an end of said feeder cable on the side of said antenna element (2) and said second coil element (L₂) connects said antenna element to the end of said cable, said capacitive element being a ground stray capacitance (C f ) of said feeder cable.
Claim 10
Dependent Claim
66 words
A reception system according to one of claims 1 - 8, characterized in that said matching means comprises a core member (TC) constituting said inductance element (L₃), permeability of said core member being set to decrease between lower and upper ends of a reception band with increase of frequency so that a resonance frequency of said parallel resonance circuit (31) increases as a reception frequency increases.
Claim 11
Dependent Claim
42 words
A reception system according to claim 9, characterized in that said inductance element comprises series-connected first and third coil elements (L₁, L₃), said third coil element including said core member (TC) serving as said matching means and having said frequency responsive characteristic.
Claim 12
Dependent Claim
50 words
A reception system according to claim 10, characterized in that comprising a second parallel resonance circuit (32) including a capacitor element (C₆) parallel-connected with said third coil element (L₃), said second parallel resonance circuit being set to resonate at a frequency location on the lower side of the reception band.
Claim 13
Dependent Claim
57 words
A recepiton system according to claim 1, characterized in that said antenna element comprises defogging heater conductors (2) arranged on a rear window glass (1) of a motor vehicle, and a pair of choke coils (11a, 11b) is inserted in a pair of power feed lines (12, 13) for feeding a heating current to said heater conductors.
Claim 14
Dependent Claim
31 words
A reception system according to claim 12, characterized in that a part or whole of said inductance element (L₁) of said parallel resonance circuit (26, 31) consists of said choke coils.
References Cited (Backward Citations)
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