Charge-coupled-device based transmitters and receivers

• US 5,557,641 A
• Filed: 05/19/1994
• Issued: 09/17/1996
• Est. Priority Date: 03/04/1994
• Status: Expired due to Term

• Current Assignee: Exelis Incorporated (L3Harris Technologies, Inc.)
• Original Assignee: Stanford Telecommunications, Inc. (Nokia Corporation)
• Inventors: Weinberg, Aaron
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US08/246,243
• Time in Patent Office: 852 Days
• Field of Search: 375/219, 375/222, 375/295, 375/343, 375/350, 375/296, 375/297, 455/91, 364/604, 364/724.13, 364/724.16, 364/819, 332/123, 332/125, 332/159, 332/160
• US Class Current: 375/295
• CPC Class Codes: F02B 2075/027 four
• CPC Class Codes: G01S 7/285 Receivers
• CPC Class Codes: H04L 27/20 Modulator circuits; Transmitter circuits

Abstract

A radio transmitter having a source of first signals for radio transmission, includes a modulator for modulating the first signals on an intermediate carrier frequency second signal to produce a third signal. A charge coupled device (CCD) is connected to receive and process the third signal in the absence of digital waveform shaping and digital-to-analog conversion. The CCD has a sampling rate which is a multiple of the intermediate carrier frequency second signal to provide aliased fourth signal components that are spectrally spaced in accordance with the multiple and provide upconversion to a fifth signal. A bandpass filter receiving the fifth signal is centered around a selected aliased signal component and a power amplifier/antenna means coupled to receive said selected aliased component for transmission. In a preferred embodiment, the multiple is 4. Moreover, the tap weights of the CCD are selected to provide wave shaping of the aliased fourth signal components. A transceiver including the radio transmitter has a radio receiver, with the radio receiver having a CCD signal processing circuit for receiving and demodulating received radio signals.

Claims

1. A radio transmitter having a source of first signals for radio transmission, means for modulating said first signals on an intermediate carrier frequency second signal to produce a third signal, a charge coupled device (CCD) connected to receive and process said third signal in the absence of digital waveform shaping and digital-to-analog conversion, said CCD having a sampling rate which is a multiple of said intermediate carrier frequency second signal to provide aliased fourth signal components that are spectrally spaced in accordance with said multiple of said intermediate carrier frequency second signal and provide upconversion to a fifth signal, a bandpass filter receiving said fifth signal, said bandpass filter being centered around a selected aliased signal component and a power amplifier/antenna means coupled to receive said selected aliased component for transmission.

2. The radio transmitter defined in claim 1 wherein said multiple is 4.

3. The radio transmitter defined in claim 1 wherein the tap weights of said CCD are selected to provide wave shaping of said aliased fourth signal components.

4. A transceiver comprising a radio transmitter as defined in claim 1 and a radio receiver, said radio receiver having a CCD signal processing circuit for receiving and demodulating received radio signals.