Design of a High Frequency Ring Oscillators and Drive a Standard 50 Ω Load
In this project, you have to design and simulate a ring oscillator and rig oscillator will drive a standard load, which could be an antenna, RF circuit or any other standard blocks.
A ring oscillator is a cascade of multiple (odd number) of inverting stages. In the simplest form, the inverting stage could be an inverter. By adjusting the device dimensions (i.e. MOSFET W/L ratio), supply voltage (i.e. Vdd), and number of stages the frequency of the ring oscillator can be tuned to the target frequency of operation.
The followings are the design specifications for the project
1. Show the design and simulation of a CMOS (PMOS and NMOS) inverter using Cadence. Show the transient outputs of the CMOS inverter.
2. Cascade odd number of identical CMOS inverters and make a feedback connection from the output of the last stage (i.e. last inverter) to the input of the first stage (i.e. first inverter).
3. Perform transient simulation and check the frequency of oscillation.
4. Adjust the device dimensions (i.e. MOSFET W/L ratio), supply voltage (i.e. Vdd), and number of stages to tune the oscillation frequency close to 100 MHz.
5. To drive a standard 50 Ω load resistor, design a matching network and connect it at the output of the ring oscillator.
[Note:
Make sure the matching network does not affect the DC bias of the ring oscillator. Matching network with series capacitor will be a preferable one to resolve the problem.]
6. Show the transient simulation results of the ring oscillator connected with the matching network and the 50 Ω load resistor.
Write a formal report (using IEEE format) to show your Cadence software based design schematic and all of your simulation results.