EP0535800A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
General-purpose synthesizer for a radio apparatus
Assignee: Nokia Oyj
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Filing: 1992-08-26
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Granted: —
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Expires: 2012-08-26
Abstract
Abstract A synthesizer for a radio transceiver uses a Direct Digital Synthesis (DDS) system (3) to provide a modulated signal for the transmitter section. The modulated signal (So) is then mixed in a mixer (4) using a signal from a local oscillator (1) to provide the signal for transmission. The reference frequency for the DDS system is provided by the local oscillator (1) of the receiver section. The local oscillator is used to provide the signal for the mixer (4).
Inventors
- 👤 Jarmo Juhani Heinonen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 00:17
CPC Classifications
H; H03; H03C; H03C3/00; H04; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/403; H04B1/405
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
141 words
A synthesizer for a radio transceiver, the radio transceiver comprising; a receiver section for receiving a radio frequency signal and having a local oscillator for providing a local oscillator signal, and a mixer for generating a first intermediate frequency signal from the radio frequency signal and the local oscillator signal; and a transmitter section for generating a modulated radio frequency signal for transmission therefrom, the transmitter section having means for generating a modulated signal at a second intermediate frequency signal, a local oscillator for generating a local oscillator signal and a mixer for generating the modulated radio frequency signal from the modulated intermediate frequency signal and the local oscillator signal, characterised in that; the means for generating the modulated intermediate frequency signal comprises a direct digital synthesis system in which the modulated intermediate frequency signal is generated from a reference frequency.
Claim 2
Dependent Claim
141 words
A synthesizer for a radio transceiver, the radio transceiver comprising; a receiver section for receiving a radio frequency signal and having a local oscillator for providing a local oscillator signal, and a mixer for generating a first intermediate frequency signal from the radio frequency signal and the local oscillator signal; and a transmitter section for generating a modulated radio frequency signal for transmission therefrom, the transmitter section having means for generating a modulated signal at a second intermediate frequency signal, a local oscillator for generating a local oscillator signal and a mixer for generating the modulated radio frequency signal from the modulated intermediate frequency signal and the local oscillator signal, characterised in that; the means for generating the modulated intermediate frequency signal comprises a direct digital synthesis system in which the modulated intermediate frequency signal is generated from a reference frequency.
Claim 3
Dependent Claim
25 words
A synthesizer according to claim 1, wherein the direct digital synthesis system is operable to provide frequency control for the radio frequency signal for transmission.
Claim 4
Dependent Claim
25 words
A synthesizer according to any preceding claim wherein the oscillator signal for the transmitter section is generated by the local oscillator of the receiver section.
Claim 5
Dependent Claim
31 words
A synthesizer according to any preceding claim wherein a multiplier (5) is provided between the DDS system and the transmitter mixer to increase the DDS frequency to be suitable for mixing.
Claim 6
Dependent Claim
20 words
Asynthesizeraccordingtodaim2wherein in that the local oscillator frequency of the receiver is generated with the aid of a PLL synthesizer (1).
Claim 7
Dependent Claim
20 words
Asynthesizeraccordingtodaim2wherein in that the local oscillator frequency of the receiver is generated with the aid of a PLL synthesizer (1).
References Cited (Backward Citations)
No citation records indexed.
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