Investigation of high-frequency microwave ablation using floating-sleeve dipole antennas

Microwave ablation (MWA) is a promising low-cost, minimally invasive alternative to surgical resection for the treatment of many different types of cancerous tumors. High frequency MWA antennas are desirable because they are smaller, which makes them less invasive and able to reach tumors not accessible by lower frequency MWA antennas, but the vast majority of past MWA work has focused on the use of frequencies below 2.5 GHz. The few exceptions involve antennas operating at 9.2 GHz (Hodgson et al., Brit. J. Obstet Gynaec, 106, 684–694, 1999), 14.5 GHz (Hancock et al., IEEE Trans. Microw. Theory Techn., 61, 5, 2230–2241, 2013), 18 GHz (Yoon et al., Int. J. Cancer, 129, 1970–1978, 2011), and 24 GHz (Komarov, Eur. Phys. J. Appl. Phys., 68, 2014). In the past, greater attention has been given to lower-frequency designs, in part due to concerns that the decrease in microwave penetration depth with increasing frequency would preclude the creation of sufficiently large volumes of ablated tissue.