Tunable Filters Using Charge Transfer Devices.
Abstract
The report summarizes progress to date in the development of a charge coupled device (CCD) tunable bandpass filter. Several design approaches are discussed, including (1) two 500-stage filters with about 40 dB sidelobes and a 1% 3dB bandwidth, (2)a 403-stage filter with 35 dB sidelobes and 1.25% bandwidth, (3) a 403-stage filter with 55 dB sidelobes and 1.40% bandwidth, and (4) a pair of 250-stage multiplexed filters which simulate a 500-stage device with 1% bandwidth and 35 dB sidelobes. The Dolph-Chebyshev tap weighting technique is described. Computer simulations show that sidelobe rejection of 40 dB can be achieved with charge transfer efficiency CTE = or > 0.999, which has been achieved in buried channel CCD's up to 40 MHz. The effects of expected tap weight noise are not serious limitations in device performance for our design goals. Noise limitations are calculated, and an on-chip input amplifier is described. Experimental results are presented from a 101-stage filter designed for 29 dB sidelobes and a 4% bandwidth. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1974
- Accession Number
- AD0782818
Entities
People
- C. R. Hewes
- D. D. Buss
Organizations
- Texas Instruments