چكيده به لاتين
With the rapid growth of wireless telecommunication systems, many efforts have been made to make transmitters-receivers with greater efficiency, smaller size and lower power consumption. One of these telecommunication systems is the Global Navigation Satellite System (GNSS. Extensive demand and the being of large markets have led many countries to create their own GNSS systems, among which the GPS system from the United States and GLONASS from Russia are the most important. GNSS signals essentially use two RF bands: 1.2 GHz and 1.57 GHz. The oscillator has the task of adjusting the transmitter-receiver's work frequency in one of these two bands. Today, an oscillator that can be used in a wider range of telecommunication frequencies with less noise and lower power consumption is more appropriat.
In this thesis, a voltage controlled LC oscillator is proposed for various frequency band. In the design of the oscillator, the active inductor has been used with a controllable negative resistance method, which improves phase noise and has low power consumption. The circuit is simulated by ADS and CADENCE, and the simulation results in the 0.18 μm TSMC CMOS technology shows that the oscillator has a phase noise of -138 dBc/Hz in band 1(1.2 GHz) and at offset 1 MHz. The adjustable frequency range is from 0.72 to 1.25 GHz. Power consumption in the oscillator core is 2.6 to 3.4 mW, which is supplied from 1.8 volt source. Also, the oscillator has a phase noise of -136.32 dBc/Hz in band 2(1.57 GHz) and at 1 MHz offset. The adjustable frequency range is 1.28 to 1.85 GHz. Power consumption in the oscillator core is also 2.6 to 3.5 mW. Also, THD is 10% to 12%. The simulation results indicate that the power consumption has been reduced by about 50%, and the phase noise has been improved by 16% to -136.174 dBc/Hz.
