IOT and chip design

In this section, I will show you the topology of ring oscillator based on OTA. Figure 1 is the topology of OTA. This OTA has two inputs and outputs which delay 180 degree. Figure. 1 Topology of OTA Figure 2 is the AC response of OTA. In this simulation, this OTA can be seen as a amplifier and also has high transfer speedn.  Figure .2 AC response of OTA Figure 3 is the topology of Ring oscillator. It only combine two OTA. Moreover, it can output two opposite signal in the same time.  Figure 3. Ring oscillator based on OTA Figure 4 is the simulation of Ring oscillator, and its frequency is 3 G Hz.  Figure 4. Simulation of Ring oscillator

Inductor on print circuit board (PCB) is a complicated. In Figure.1, it shows some factors, which may influence the inductance and q factor. W is the width of trace line. S is the space between two different trace lines. D is outer diameter, N is number of windings, x is the difference of the sides of the square, and d is inner diameter. The formula in this spiral inductor is \[L=K_1u_0\frac{N^2 D_avg}{1+K_2p}\] \[D_{avg}=\frac{(D-d)}{(D+d)}\] Figure. 1 Factor of Inductor Figure. 2 (a) is the 3D view of inductor design. This design can provide high inductance and magnetic field. Figure. 2(b) is the equivalent circuit of Figure. 2 (a). Thus, the maximum inductance value by stacking two spirals. The thickness may influence the inductance slightly. On the other hand, thickness would influence parasitic capacitor and change the q factor.   Figure. 2 3D view of inductor design(a) and circuit(b)