A new 5 and 10 MHz high isolation distribution amplifier

Increasing performance demands timing have made NIST´s present amplifier system obsolete. A new design providing improved phase stability with temperature, harmonic purity, and phase noise is presented. By building on previous designs, a modified cascode amplifier was created with performance increases of more than 10 fold in phase noise, temperature coefficient and isolation. An input-output isolation of 140 dB and channel to channel isolation of greater than 125 dB was achieved. Phase noise performance of -152 dBc/Hz at 1 Hz with a noise floor of -170 dBc/Hz was also achieved. Input and output matching provide average return losses greater 30 dB. Harmonics are all -45 dBc or better at an output of +13 dBm and the temperature coefficient of output phase is less then 1 ps/°C