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Metastasis is the leading cause of death in breast cancer patients and an appropriate detection of metastasis can provide better prognosis and quality treatments. Microwaves can reveal the unique electromagnetic properties of materials, and this study aims to unleash the electromagnetic properties of breast cancer cells, especially, metastasized cancer cells in the lymph nodes, using broad-band microwaves in attempts to detect metastases. To distinguish the cancer-specific patterns of cancer tissues, three primary microwave parameters were assessed, i.e., permittivity in mid-band frequency (3-5 GHz), conductivity in high-band frequencies (25-30 GHz) and slope changes of permittivity at high-band frequencies (15-30 GHz). An additional parameter, Cancer Metastasis Index (CMI), was developed to effectively represent all parameters. Broadband microwave scanning can reveal cancer specific electromagnetic behaviors in all three parameters, and these were reliably reflected by CMI. CMI effectively magnified the difference of the electromagnetic properties between normal nodal tissues and cancer tissues. immunohistochemistries were performed to verify the origin of electromagnetic changes represented by CMI values.

Air-gap overlay CPW couplers and low-loss series metal-to-metal contact microelectromechanical system (MEMS) switches have been employed to reduce the loss of reflection-type MEMS phase shifters at V-band. Phase shift is obtained by changing the lengths of the open-ended stubs using series MEMS switches. A 2-bit [135] reflection-type MEMS phase shifter showed an average insertion loss of 4 dB with return loss better than 11.7 dB from 50 to 70 GHz. The chip is very compact with a chip size as small as 1.5 mm /spl times/ 2.1 mm.

In this work, we have characterized the permittivity of human epidermis (outer skin layer) using microwave up to 110 GHz. A one mm-diameter coaxial probe was adopted to increase measuring bandwidth as well as to enhance the spatial resolution. Pork was used to discriminate the permittivities between muscle tissues and fat tissues. The influence of the sample thickness was also. studied. Considering several factors, the permittivity was measured on epidermis of the human palm and the wrist. In addition, a relaxation phenomenon observed in the wrist skin, revealed by Cole-Cole parameters, suggested that it originated from high water content beneath the thin epidermis of the wrist skin. A relaxation phenomenon revealed by Cole-Cole parameters was observed in the wrist skin. This explains that high water content cells exist beneath the thin epidermis of the wrist skin.