Design of spiral antennas for radiometric temperature measurement.
Design of spiral antennas for radiometric temperature measurement.
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用于辐射温度测量的螺旋天线设计。
DOI：
10.1109/iembs.2004.1403726
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Stauffer,PR
中科院分区：
文献类型：
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作者：
Rolfsnes,HO;Maccarini,PF;Jacobsen,S;Stauffer,PR
我们正在开发一种微波热疗系统，用于治疗乳腺癌的胸壁复发。为了改善加热装置的功率控制，我们打算在治疗过程中使用辐射测量法无创地测量肿瘤温度。我们正在设计单臂阿基米德螺旋作为接收天线，用辐射计收集来自不同组织体积的热辐射，频率为1.9-2.3 GHz和3.7-4.2 GHz。我们对天线进行了数值模拟。首先，我们从馈线阻抗匹配的角度研究了天线。其次，我们研究了螺旋辐射到受损组织的辐射机制。在匝距较小的情况下，螺旋上的表面电流在几个相邻的绕组上相位一致，从一个圆形的波长相关区域产生强烈的辐射。在这些位置，表面电流在螺旋的相反侧也处于相位，与广泛分散的模式相比，有助于获得更集中的峰值辐射模式，具有更深的能量穿透。最后，研究了螺旋馈点到辐射区的距离对天线效率的影响。我们发现这个距离应该最小化，以减少功率损失，从不太有用的内部旋转的螺旋。这些设计参数的优化可以显著提高天线效率，提高微波辐射测量的测深能力。
We are developing a microwave hyperthermia system for the treatment of chestwall recurrence of breast cancer. To improve power control of heating applicators, we intend to measure tumor temperature noninvasively during treatment, using radiometry. We are designing single-arm Archimedean spirals for use as receive antennas with a radiometer collecting thermal radiation from different tissue volumes at 1.9-2.3 and 3.7-4.2 GHz. We modeled the antennas numerically. First, we studied the antennas in terms of impedance matching to feedlines. Second, we investigated radiation mechanisms of the spirals radiating into lossy tissue. For small spacing between turns, the surface currents on the spiral were in phase on several neighboring windings, producing strong radiation from a circular, wavelength related region. At these locations, surface currents were also in phase on opposite sides of spiral, contributing to a more centrally peaked radiation pattern with deeper energy penetration than is obtained with a widely dispersed pattern. Finally, we studied the effect of distance from the spiral feedpoint to the radiating region on antenna efficiency. We found this distance should be minimized to reduce power loss from the less useful inner turns of the spirals. The optimization of these design parameters may produce significant improvement of antenna efficiency and improve depth-sensing capability of microwave radiometry.