comparatively high voltage generated by the MTJ STO can be obtained. This voltage will be used as the reference voltage to compare with the voltage signals obtained from the MTJ STO together with the Balun-LNA. The transient simulation of the system is then conducted at the same biasing condition. The obtained time domain signals, including the voltage generated by the unloaded MTJ STO, the voltage that can be delivered from the MTJ STO to the Balun-LNA, and the amplified voltage at the differential output of the Balun-LNA, are plotted in Fig. 6.

The output signals of the MTJ STO before and after being connected by the Balun-LNA show that the DC voltage is sustained due to employed bias-T, and the DC resistance ($R_\text{DC}$) is close to 50 $\Omega$. In addition, approximately 2/3 of the AC voltage generated by the MTJ STO is delivered to the Balun-LNA, which is due to the fact that an AC voltage divider is formed between $R_\text{DC}$ and the input impedance of the Balun-LNA ($Z_\text{in}$). To quantify the power delivery and amplification so as to evaluate the hybrid simulation, PSDs of these signals are plotted in Fig. 7.

Figure 7 shows that the power delivered from 