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Support Circuit Design



                                                                          Support Circuit Design  347































                        Figure 8.14 A wideband, low-distortion SPDT PIN diode switch.















                        Figure 8.15 A shunt PIN diode switch.


                        2. C   C   1 ohm (X ) at f .
                            B     C           C    r
                               DC bias 	 0.9
                        3. R ≈
                                   25 mA
                             DC bias is in volts.

                        Small-signal series PIN switch (Fig. 8.16). When this switch is in the on condi-
                        tion ( 5 V or higher at V   ), the insertion loss is low, while the return loss
                                                CNTRL
                        is high. When the switch is in the off condition (0 V), the signal is severally
                        attenuated by the diode, while also creating a low return loss.
                        1. RFC   500 ohms (X ) at f .
                                              L    r

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