Four pole elliptic band pass filter on GaAs substrate

In this paper a novel result for phase noise oscillator is presented. A four pole elliptic band pass filter is used to decrease the phase noise. The phase noise oscillator with RT/Duroid 5880 substrate with ϵ_r = 2.2, h = 31 mil at offset frequencies 100 KHz and 1 MHz is equal to -122 and -140 dBc/Hz, respectively, and is -128 and -146 dBc/Hz for GaAs substrate with ϵ_r = 12.90 and h = 100 μ m in the same frequencies, respectively. The loss for GaAs sabstrate is less than an RT/Duroid 5880 substrate. The phase noise is improved for GaAs in comparison to RT/Duroid 5880 substrate about 6 dBc at 100KHz and 1MHz offset frequencies.