| 摘要 |
<p>D-22,344 BASEBAND SPECTRUM GENERATOR USING LOGIC LEVEL INPUT PULSES by Lawrence E. Getgen A pulse source provides logic level pulses, having a pulse rate of fb and a pulse width of t', to the input of a switching amplifier having an open collector output. A relatively high voltage, greater than the logic level voltage amplitude, is applied to the collector via a current limiting resistor R and the primary winding of a transformer. The logic level pulses switch the switching amplifier on at intervals of T = l/fb for a duration of t' seconds. The switching current in the primary winding of the transformer induces a current in the secondary winding thereof which has a spectrum that includes a spectral element at the switching rate fb and multiples thereof. This output spectrum and power level depend upon the pulse amplitude and the pulse width t'. The output power is proportional to the amplitude of the switched pulse and the pulse width t', whereas, the spectral bandwidth is inversely proportional to t'.</p> |
