## 3 Results
### Passive EQ-Lumped Elements, Synthesis
#### 3.1.3 Rlc Eq  
Implementing RLC EQ results in attenuation of the transmitted signal as the peaks no longer pass the thresholds. The waveforms and eye diagrams for pre-, post-, and pre  
Figure 16: RL EQ: (**a**) circuit, (**b**) pre-, (**c**) post-, (**d**) pre- and post- and (**e**) overlaid.  
Figure 17: Insertion (**a**) and return loss (**b**) in the RC EQ: pre- (light green), post- (dark green), pre- and post- (red), and overlaid.  
and post- microstrip line. The SUBCKT \"Filter\" is the actual microstrip line. The variant of either pre- and post- EQ gives less attenuated amplitude. The maximum obtained in pre-EQ is 924.26 mV and in post-EQ the maximum is 934.53 mV and in case of pre- and post- the maximum amplitude is 803.41 mV.  
Another variant of EQ filter is presented in the below Figure 18. The new EQ filter is slightly improving the eye opening for the case of implementation as presented in (a) comparing to the variant in Figure 19a. In Figure 18b, with EQ connected in front of the link and Zmatch connected derivative to the previous RC structure, both eye diagrams are represented freezing in the graph, the results given by Figure 19a output circuit.  
In frequency domain, we can see the RL and IL after introducing the EQ in the system. The IL will need to have a more flat curve due to high frequency compensation. For the  
Figure 19: RLC EQ: (**a**) circuit, (**b**) pre-, (**c**) post-, (**d**) pre- and post-, and (**e**) overlaid.  
Figure 18: Variant of RLC EQ (**a**) circuit schematic and (**b**) eye diagrams with \(Z_{\text{match}}\) connected to the RC.  
present design the RL and IL are represented in Figure 20 below. The best match is obtained using the RLC EQ at the both ends of the microstrip, \(-61\) dB at 9.59 GHz.
If the length will increase, the IL will rise. Keeping the 10 Gbps data rate, the new eye diagrams for the three variants are presented in Figure 23 with Figure 23a for RL EQ. Figure 23b for RC EQ and Figure 23c for RLC EQ. The first column in representation of the length is set to 20 cm and the second one with a length of 50 cm. The eye diagrams still fit the height and width margins for 20 cm with overshoot and undershoot but highly exceeds the limits for 50 cm, still with clear open eye.  
Figure 23: Eye diagrams for increased line length for RL (**a**), RC (**b**), and RLC bridge T variant (**c**) (from left to right): 20 cm and 50 cm.  
Figure 22: Variant of Bridge T EQ (**a**) circuit schematic and (**b**) eye diagrams in pre-, post-, and pre- and post- line for Bridge T and RLC EQ modified.  
The EQ cannot provide the function of equalization for the given IL at these lengths as distortions increase with the length of the interconnection. In this case, a new synthesis has to be done.  
The waveform at the output of RC and RLC type of EQ are represented in Figure 24. In the case of RC EQ type implemented, only the pre\(-\)EQ variant will reach the high level but the undershoot exceed the low level. The peaks pass the low level as it is represented in the voltage variation in RLC EQ case.  
Based on the three variants implemented above one can select based on constraints applied to the own system.