| 摘要 |
An ultrawide-bandwidth, low-noise optical receiver is disclosed. The receiver comprises a photodiode (402) connected to a high-impedance three-stage (421, 422, 423) HEMT preamplifier through an inductive/resistive modified T-network (404) the latter circuit enhancing the high-frequency response of the first stage. Each stage includes an HEMT amplifier (408, 408, 410) and an interstage microwave matching circuit (405, 406, 407) configured as a modified T-network having wire-bond inductances as the series-arm impedances and a coplanar waveguide in series with a resistor as the shunt-leg impedance. The first stage provides signal gain and transforms the high input impedance to an intermediate value. The second stage provides additional gain at the intermediate impedance level and the third stage provides output impedance matching to a conventional 50 OMEGA system.
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