Design of a high-efficiency v.h.f. double-sideband diminished-carrier transmitter having low spurious emission

Interest has recently been shown in the use of d.s.b. diminished carrier for the mobile land radio service. Difficulties in the design of a suitable transmitter employing a conventional exciter-amplifier technique are described. A method that overcomes these difficulties is discussed, and a suitable design presented. A transmitter capable of delivering 38 W peak envelope power with an 18 V supply has been built. The spurious responses close to the wanted sidebands, were almost one order of magnitude lower than can be achieved with the conventional exciter/linear-amplifier technique. Power efficiency was also greatly improved.