US3979701A
Expired / Lapsed
US
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Non-recursive digital filter employing simple coefficients
Assignee: International Telecommunications Satellite Organization
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Filing: 1975-06-17
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Granted: 1976-09-07
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Expires: 1995-06-17
Abstract
Abstract A non-recursive digital filter is disclosed, composed of a cascaded plurality of basic sections, each of which is characterized by coefficient values of integer powers of two's. No hardware multipliers are required in the filter and the operating speed is several times faster than other filters which utilize multipliers.
Inventors
- 👤 Atsushi Tomozawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:48
CPC Classifications
H; H03; H03H; H03H17/00; H03H17/02; H03H17/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
101 words
A non-recursive digital filter comprising: a. a first section of N delay elements, the coefficient value of all the taps of said delay elements being one; b. a second section of 2M delay elements, the coefficient value of all the taps of said delay elements being an integer power of two; c. said first section utilized for forming the desired loss characteristics of said filter and said second section utilized for shaping the passband of said filter; and d. said first and second sections operably coupled such that the resulting grouping has a tap coefficient of an integer power of two.
Claim 2
Dependent Claim
101 words
A non-recursive digital filter comprising: a. a first section of N delay elements, the coefficient value of all the taps of said delay elements being one; b. a second section of 2M delay elements, the coefficient value of all the taps of said delay elements being an integer power of two; c. said first section utilized for forming the desired loss characteristics of said filter and said second section utilized for shaping the passband of said filter; and d. said first and second sections operably coupled such that the resulting grouping has a tap coefficient of an integer power of two.
Claim 3
Dependent Claim
40 words
The apparatus of claim 1 wherein said section of N delay elements has an impulse response of (N+1) consecutive impulses of unitary amplitude where n is the order of the section and, wherein the transfer function in Z is: ##EQU7##
Claim 4
Dependent Claim
69 words
The apparatus of claim 2 wherein said section of 2M delay elements has an impulse response comprising of one main response of unitary amplitude and two secondary responses of amplitude α, separated by m clock intervals, before and after the main response, and wherein the transfer function in Z is: H(Z) = α + Z.sup..sup.-m + α Z.sup..sup.-2m, where α = ± 2.sup. -k , k being a constant.
Claim 5
Dependent Claim
31 words
The apparatus of claim 3 wherein the DC gain for said section of N delay elements is (N+1) and the DC gain for said section of 2M delay elements is (1+2α).
Claim 6
Dependent Claim
34 words
The apparatus of claim 4 wherein the transfer function in frequency of said first section of N delay elements is: ##EQU8## where fs is the sampling frequency and N is an even integer (N=2k).
Claim 7
Dependent Claim
36 words
The apparatus of claim 4 wherein the transfer function in frequency of said first section of N delay elements is: ##EQU9## where fs is the sampling frequency and N is an odd integer (N = 2K+1).
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) | 1979-09-07 | 1980-03-08 | 1980-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-07 | 1984-03-08 | 1984-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-07 | 1988-03-08 | 1988-09-07 | $7700.00 | Window Closed / Lapsed |