Patent US2254085A successfully refreshed from Google Patents.
Patent US4399558A successfully refreshed from Google Patents.
US4399558A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cascaded digital broadcast transmitter
Assignee: RCA Corp
•
Filing: 1981-06-29
•
Granted: 1983-08-16
•
Expires: 2001-06-29
Abstract
Abstract A digital AM broadcast transmitter features a plurality of stages that are controlled by a digital signal representing an audio modulating signal. At least some of the stages are cascade coupled together using transformers. This reduces the need for high turns ratios and allows most or all transformers to be identical.
Inventors
- 👤 Charles F. Smollin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:20
CPC Classifications
H; H03; H03C; H03C1/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
93 words
An apparatus for generating an amplitude modulated signal from a weighted digital signal, said apparatus comprising generating means for generating a plurality of equal amplitude signals in accordance with said digital signal, and combining means for combining at least some of said plurality of signals to form said amplitude modulated signal, said combining means comprising a plurality of cascade coupled transformers having the primary of one transformer coupled to the secondary of another transformer, at least some of said transformers having a turns ratio in accordance with said weighting of said digital signal.
Claim 2
Independent Claim
93 words
An apparatus for generating an amplitude modulated signal from a weighted digital signal, said apparatus comprising generating means for generating a plurality of equal amplitude signals in accordance with said digital signal, and combining means for combining at least some of said plurality of signals to form said amplitude modulated signal, said combining means comprising a plurality of cascade coupled transformers having the primary of one transformer coupled to the secondary of another transformer, at least some of said transformers having a turns ratio in accordance with said weighting of said digital signal.
Claim 3
Dependent Claim
23 words
An apparatus as claimed in claim 1, wherein said weighting is binary and at least some of said transformers have 2:1 turns ratios.
Claim 4
Dependent Claim
22 words
An apparatus as claimed in claim 1 wherein said combining means comprises means for cascade combining all of said plurality of signals.
Claim 5
Dependent Claim
36 words
An apparatus as claimed in claim 1 wherein said combining means comprises means for cascade combining only some of said plurality of signals and for series coupling together the remaining signals of said plurality of signals.
Claim 6
Dependent Claim
26 words
An apparatus as claimed in claim 1 wherein said generating means comprises a plurality of bridge amplifier stages, and a voltage source coupled to said stages.
Claim 7
Dependent Claim
32 words
An apparatus as claimed in claim 1 further comprising an analog-to-digital converter having an input for receiving an analog modulation signal and a plurality of output means for providing said digital signal.
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) | 1986-08-15 | 1987-02-14 | 1987-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-15 | 1991-02-14 | 1991-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-15 | 1995-02-14 | 1995-08-16 | $7700.00 | Window Closed / Lapsed |