US4776039A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Receiver for mobile communication systems
Assignee: NEC Corp
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Filing: 1986-01-27
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Granted: 1988-10-04
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Expires: 2006-01-27
Abstract
Abstract A receiver suitable for use at very high frequency bands in which an antenna output is filtered, amplified and then mixed with a local oscillator in a frequency convertor to provide an intermediate frequency. The intermediate frequency is provided to a quadrature detector which directly converts the intermediate frequency into two baseband signals whose phases differ by 90°. The baseband signals are independently amplified and demodulated in a common demodulator which provides a single output signal.
Inventors
- 👤 Yoshihiko Akaiwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:25
CPC Classifications
H; H03; H03D; H03D3/00; H03D3/007; H03D7/00; H03D7/16; H03D7/161; H03D7/165
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
123 words
A receiver for mobile communication systems comprising: means for receiving a signal modulated by an original signal; first filter means for band-limiting said received signal; a frequency converter means having a single stage, including a frequency mixer and a band-pass filter, for converting the output signal of said first filter means into an intermediate frequency signal; detector means for quadrature-detecting said intermediate frequency signal with a local oscillator signal whose frequency is substantially equal to the center frequency of said intermediate frequency signal and thereby providing two baseband signals; first and second channel filter means for band-limiting each of said two baseband signals; and demodulator means for demodulating the output signals of said first and second channel filter means into said original signal.
Claim 2
Dependent Claim
123 words
A receiver for mobile communication systems comprising: means for receiving a signal modulated by an original signal; first filter means for band-limiting said received signal; a frequency converter means having a single stage, including a frequency mixer and a band-pass filter, for converting the output signal of said first filter means into an intermediate frequency signal; detector means for quadrature-detecting said intermediate frequency signal with a local oscillator signal whose frequency is substantially equal to the center frequency of said intermediate frequency signal and thereby providing two baseband signals; first and second channel filter means for band-limiting each of said two baseband signals; and demodulator means for demodulating the output signals of said first and second channel filter means into said original signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-04 | 1992-04-04 | 1992-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-04 | 1996-04-04 | 1996-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-04 | 2000-04-04 | 2000-10-04 | $7700.00 | Window Closed / Lapsed |