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United States Patent [w]
Evans et al.
[ii] Patent Number:  Date of Patent:
MPT 1550: Performance Specification for Analogue Multipoint Video Distribution Systems (MVDS), Transmitters and Transmit Antennas Operating in the Frequency Band 40.5 Ghz-42.5 Ghz, pp. 1-30.
"The M3VDS Saxmundham Demonstratormultichannel TV
distribution by mm-waves", British Telecom Technology
Journal, vol. 7, No. 1, Jan. 1989, pp. 5-19.
1978 FCC Petition on Xerox Telecom Network, pp. 12-15.
"Local Node Antenna Patterns", pp. 30-32.
Electronics Weekly, Apr. 21, 1993, p. 2.
"29GHz Radio Systems -Safety Consideration".
Electronics World & Wireless World, Dec. 1993, "Antenna
Boost for Cellular Phones", p. 974.
Primary Examiner—Doris H. To
Attorney, Agent, or Firm—Robert J. Kraus
In a cell of a microwave cellular video distribution system, e.g a multichannel video distribution system operating at frequencies of around 29 GHz or 40 GHz, the transmitting antenna is composed of individual antenna sectors (62a,62fc, 62c . . . ) for transmitting the microwave signal towards different sectors (216a,216fc,216c . . . ) of the cell. In accordance with the present invention, a respective monitor (D,R) is present in each of the different sectors (216a,216fc, 216c . . . ) of each/the cell to monitor the microwave signal transmitted in that sector. The antenna sectors (62a,62fc, 62c . . . ) are individually fed through controllable feed means (59,60,61) which permit individual control of the power level of the microwave signals transmitted by the individual antenna sectors (62a,62fc,62c . . . ), including the switching off of that sector. A feedback coupling (40,44,49) is present between each monitor (R,D) and the controllable feed means (59,60,61) of the respective antenna sector (62a,62fc, 62c . . . ) to control individually the power levels transmitted towards the different sectors (216a,216fc, 216c . . . ) of each cell. In this manner the transmission pattern in each cell can be controlled and adapted to improve the quality of signal reception as requested by subscribers (R), to increase the operational life of the transmitter(s) by minimizing transmitter power, and to enhance responsiveness to other desirable and/or acceptable demands placed on the signal transmission.
8 Claims, 4 Drawing Sheets