A pulsed confocal microwave technique for the detection of dielectric contrast of breast tissue

✍ Scribed by G. Bindu; Santhosh John Abraham; Anil Lonappan; Vinu Thomas; C. K. Aanandan; K. T. Mathew

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 132 KB
• Volume: 47
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/mop.21125

✦ Synopsis

eters of TSMC 0.18-m CMOS technology. The bias-resistance values and power-supply voltage are listed in Table 1. The simulations are done at 5.2 GHz with a Ϫ20-dBm RF signal and 4.82 GHz with a 4-dBm LO signal. The simulated results according to these parameters are summarized in Table 2, where we can see that the proposed mixer exhibits 6.2-dB conversion gain, 4.8-dBm linearity, and 79.7-dB LO-to-RF isolation.

The proposed new CMOS MMIC mixer is measured on board and the mixer's chip micrograph is shown in Figure 3. The measured results are illustrated in the following figures. In Figure 4, the input ports' return losses are Ϫ20 and Ϫ12 dB in the RF and LO bands, respectively. And the output-port return loss is Ϫ11.5 dB in the IF band. The measured results of conversion gain and IP 1dB are 3.7 dB and Ϫ6.5 dBm with respect to the 6.2-dB and Ϫ5-dBm simulated results, as shown in Figure 5, and the difference between the simulated and measured results of the CG are due to the uncounted substrate losses of die and the board. The measured result of IIP 3 is 12 dBm with respect to the 4.8-dBm simulated result, as shown in Figure 6. Finally, Figure 7 shows that the measured and simulated results of isolation are all better than 30 dB; especially, the LO-to-RF isolation for the measured and simulated results are 43 and 79.7 dB at 4.82 GHz, respectively. Due to the silicon-substrate loss and bounding-wire coupling, the measured data of LO-to-RF isolation are lower than the simulated data. The simulated and measured results are summarized in Table 2.

CONCLUSION