| 摘要 |
A variable attenuator formed from a combination of PIN diodes is provided. The PIN diodes may be coupled in a "T," "p" or other appropriate configuration. At radio frequencies (RF), a PIN diode acts as a variable resistor with a resistance value based on the bias current of the PIN diode. To control the attenuation level of the variable attenuator, the bias current of the PIN diodes are selectively adjusted. Digital values relating to selected bias currents, and thus selected attenuation levels, are stored in a memory. These digital values are provided as control signals that set the bias current levels for the PIN diodes. The bias current levels control the attenuation level of the variable attenuator.
|
