摘要
A 50 MHz-1 GHz low noise and high linearity amplifier monolithic-microwave integrated-circuit （MMIC） for cable TV is presented.A shunt AC voltage negative feedback combined with source current negative feedback is adopted to extend the bandwidth and linearity.A novel DC bias feedback is introduced to stabilize the operation point,which improved the linearity further.The circuit was fabricated with a 0.15μm InGaAs PHEMT （pseudomorphic high electron mobility transistor） process.The test was carried out in 75Ωsystems from 50 MHz to 1 GHz.The measurement results showed that it gave a small signal gain of 16.5 dB with little gain ripples of less than±1dB.An excellent noise figure of 1.7-2.9 dB is obtained in the designed band.The IIP3 is 16 dBm, which shows very good linearity.The CSO and CTB are high up to 68 dBc and 77 dBc,respectively.The chip area is 0.56 mm^2 and the power dissipation is 110 mA with a 5 V supply.It is ideally suited to cable TV systems.
A 50 MHz-1 GHz low noise and high linearity amplifier monolithic-microwave integrated-circuit （MMIC） for cable TV is presented.A shunt AC voltage negative feedback combined with source current negative feedback is adopted to extend the bandwidth and linearity.A novel DC bias feedback is introduced to stabilize the operation point,which improved the linearity further.The circuit was fabricated with a 0.15μm InGaAs PHEMT （pseudomorphic high electron mobility transistor） process.The test was carried out in 75Ωsystems from 50 MHz to 1 GHz.The measurement results showed that it gave a small signal gain of 16.5 dB with little gain ripples of less than±1dB.An excellent noise figure of 1.7-2.9 dB is obtained in the designed band.The IIP3 is 16 dBm, which shows very good linearity.The CSO and CTB are high up to 68 dBc and 77 dBc,respectively.The chip area is 0.56 mm^2 and the power dissipation is 110 mA with a 5 V supply.It is ideally suited to cable TV systems.
