EP0800283A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Transmitter/receiver for transmitting and receiving of an RF signal in two frequency bands
Assignee: Nokia Oyj
•
Filing: 1997-03-20
•
Granted: —
•
Expires: 2017-03-20
Abstract
Abstract The object of the invention is a transmitter/receiver for transmitting and receiving of an RF signal in two frequency bands. In the solution according to the invention, a transmitter/receiver is used which is based on direct conversion and in it, when operating in both frequency bands, the mixing frequency is formed by means of the same synthesizer (340). This is implemented preferably in such a way that in the higher operating frequency, the frequency of the output signal of the synthesizer is used as such as a mixing frequency and when operating in the lower operating frequency, a mixing frequency is used which is obtained by dividing the frequency of the output signal of the synthesizer by two or a larger integer in the divider (311, 361). When the solution according to the invention is used, many synthesizers are not needed in the transmitter/receiver and no intermediate frequency components are needed.
Inventors
- 👤 Jarmo Heinonen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 05:03
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/005; H04B1/0053; H04B1/006; H03; H03D; H03D7/00; H03D7/16; H03D7/165; H03J; H03J5/00; H03J5/02; H03J5/0245; H03J5/0272; H04B1/38; H04B1/40; H04B1/403; H04B1/406
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
261 words
A direct conversion transmitter/receiver which operates in two separate frequency bands, and in which the first frequency band comprises the first transmitting frequency band and the first receiving frequency band and the second frequency band comprises the second transmitting frequency band and the second receiving frequency band, and in which - said receiver comprises at least one RX mixer for mixing the received signal into a baseband signal, - said transmitter comprises at least one TX mixer for mixing the baseband signal into a carrier frequency transmitting signal and - the transmitter/receiver comprises synthesizer means (340) for forming the first RX mixing signal (RXM1) to the RX mixer for mixing the signal (RXC1) received in the first receiving frequency band into a baseband signal (RXB1) and for forming the first TX mixing signal (TXM1) to the TX mixer (362, 382) for mixing the first baseband TX signal (TXB1) into the first carrier frequency TX signal (TXC1) which is in the first transmitting frequency band, characterized in that the transmitter/receiver comprises additionally - the first conversion means (311) for forming the second RX mixing signal (RXM2) from the first signal (RXS) formed by said synthesizer means for mixing the signal received in the second receiving frequency band into the second baseband RX signal (RXB2) and - the second conversion means (361) for forming the second TX mixing signal (TXM2) from the second signal (TXS) formed by said synthesizer means for mixing the second baseband TX signal (TXB2) into the second carrier frequency signal (TXC2) which is in the second transmitting frequency band.
Claim 2
Dependent Claim
91 words
A transmitter/receiver according to claim 1, characterized in that it comprises - the first RX mixer (316) for forming the quadrature component of a complex baseband signal (RXB 1, RXB2), - the second RX mixer (336) for forming the quadrature component of a complex baseband signal (RXB1, RXB2), - the first TX mixer for mixing the in-phase component of a complex baseband signal (TXB1, TXB2) into the carrier frequency and - the second TX mixer for mixing the quadrature component of a complex baseband signal (TXB1, TXB2) into the carrier frequency.
Claim 3
Dependent Claim
58 words
A transmitter/receiver according to claims 1 or 2, characterized in that said first conversion means comprise the first frequency divider (311) for dividing the frequency of said first signal (RXS) by at least two and said second conversion means comprise the second frequency divider (361) for dividing the frequency of said second signal (TXS) by at least two.
Claim 4
Dependent Claim
37 words
A transmitter/receiver according to claim 3, characterized in that said first frequency divider (311) and second frequency divider (361) comprise means (311, 361) for forming two signals which are separated by a phase shift of 90 degrees.
Claim 5
Dependent Claim
30 words
A transmitter/receiver according to any of the previous claims, characterized in that said first conversion means (311) and second conversion means (361) are at least partly the same conversion means.
Claim 6
Dependent Claim
26 words
A transmitter/receiver according to claims 3 and 5, characterized in that said first frequency divider (311) and second frequency divider (361) are the same frequency divider.
Claim 7
Dependent Claim
83 words
A transmitter/receiver according to any of the previous claims, characterized in that it comprises the first phase shifting means (312) for forming two signals which are separated essentially by a phase shift of 90 degrees of a received signal (RXC1) which is in the first frequency band and for feeding them to the first RX mixing means (316) and to the second RX mixing means (336) for forming an in-phase and a quadrature component of a complex baseband signal as a mixing result.
Claim 8
Dependent Claim
20 words
A transmitter/receiver according to claim 7, characterized in that said first phase shifting means comprise a differential RC phase shifter.
Claim 9
Dependent Claim
79 words
A transmitter/receiver according to any of the previous claims, characterized in that it comprises means (366) for forming a relative phase shift of 90 degrees between the first TX mixing result which is in the first transmitting frequency band and which is formed by said first mixer and the second TX mixing result which is in the first transmitting frequency and which is formed by said second mixer and means (366) for summing up said phase shifted mixing results.
Claim 10
Dependent Claim
61 words
A transmitter/receiver according to any of the previous claims, characterized in that it comprises means (386) for summing up the first TX mixing result which is in the second transmitting frequency band and which is formed by said first mixer and the second TX mixing result which is in the second transmitting frequency and which is formed by said second mixer.
Claim 11
Dependent Claim
19 words
The use of a transmitter/receiver according to any of claims 1-10 in a GSM and/or in a DCS system.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.