A cellular telephone system is a radio communication system in which a plurality of mobile stations operate within a cell which is serviced by a base station. There are typically a relatively large number of cells and base stations in a given service area. The base station in each cell is connected to a message switching center which in turn is connected to a public telephone system.
A recent innovation in the field of mobile radio communications is the hand held or "pocket" telephone concept. These telephones are extremely light weight, battery operated telephones that can be transported by an individual. One of the major design constraints for "pocket" telephones is the weight of such devices. These devices typically include a transceiver unit, a rechargeable battery and a whip antenna. The weight of the battery is a substantial portion of the total weight of the device. The battery must be of sufficient size to power the "pocket" telephone for a useful length of time. A relatively heavy battery enables the pocket telephone to be powered for a longer period of time, but it reduces the transportability of the "pocket" telephone. A lighter battery unit increases the transportability of the "pocket" telephone, but it reduces the useful operating time of the device between recharges.
In the field of mobile radio communications, it is well known that the electrical power consumption of the receiver can be reduced by periodically disconnecting the receiver from the battery during predetermined time periods. Typically, such battery saving devices disconnect the receiver from the battery for a period of several milliseconds. The receiver is then reconnected to the battery for a period of several milliseconds, and the receiver is capable of monitoring a control channel or receiving an incoming call. When a telephone call is established, the receiver is continuously connected to the power supply. After completion of the call, the receiver is again alternately connected and disconnected from the power supply. During the idle mode or the relatively long periods in which no calls are being made or received by the mobile station, substantial amounts of electrical energy can be conserved by disconnecting the receiver from the power supply.
One of the major components within the receiver of a mobile station that consumes substantial amounts of electrical energy is the amplifier. If the amount of power consumed by the amplifier can be reduced, the size of the battery can be made even smaller or alternatively the time between recharges can be further increased. Accordingly, there is a need for an improvement in the operation and structure of the amplifier in the receiver of a "pocket" telephone.