A DC voltage power supply for a time division multiple access (TDMA) radio system is provided. The DC voltage power supply apparatus includes an AC signal source, a switching transistor, a controlling signal source, a voltage converter circuit, and a capacitor. The AC signal source provides an AC signal to the DC voltage power supply. The switching transistor is coupled to the clock for switching on and off the clock signal. The controlling signal source is coupled to the switching transistor for turning the switching transistor off during a transmission or reception period and for turning the switching transistor on during an idle period. The voltage converter circuit is coupled to the switching transistor and generates a DC output voltage from the AC signal. Finally, the capacitor is coupled to the voltage converter such that the capacitor is charged by the DC output voltage when the switching transistor is turned on and the capacitor holds the DC output voltage by discharging when the switch is turned off.