Study on sub-millimeter wave superconducting array antenna

研究了亚毫米波超导阵列天线的设计、制造和表征。实验结果如下：(1)建立微波区贴片天线设计方法。利用传输线模型和Sonnet软件设计了谐振频率为5 GHz、输入阻抗为50欧姆的贴片天线。为了验证传输线模型的有效性，我们首先制作了Cu贴片天线，得到了输入阻抗约为50欧姆，谐振频率为50欧姆的Cu贴片天线。(2)超导贴片天线的制备与表征。利用YBCO薄膜制备了超导贴片天线。这些天线的输入阻抗略大于设计值50欧姆。超导贴片天线的增益比金膜天线的增益高2 ~ 4db。(3)等离子体耦合磁控溅射制备微波用YBCO薄膜。采用等离子体耦合磁控溅射法制备了超导天线用YBCO薄膜。所得薄膜的Tc和Jc在77K时分别为87K和4 × 10^6A/cm^2。(4)工作在毫米波和亚毫米波区域的对数周期天线研究我们设计并制作了工作在毫米波和亚毫米波区域的对数周期天线。我们确认天线的工作频率高达40千兆赫。增益与贴片天线的增益大致相同。

We have investigated the sub-millimeter wave superconducting array antenna, design, fabrication and characterization. These experimental results are as follows ;(1) Establishment of the design method of patch antenna operated at microwave region.We designed the patch antenna with a resonance frequency of 5 GHz and an input impedance of 50 ohms by the transmission line model and a Sonnet Software. In order to check the validity of the transmission line model, we first fabricated the Cu patch antenna, We could obtain the Cu patch antenna with input impedance of approximately 50 ohms and the resonance frequency of 50 ohms.(2) Fabrication and characterization of superconducting patch antenna.We fabricated the superconducting patch antenna using YBCO thin films. The input impedance of these antenna was slightly larger than that of designed value, 50 ohms. The gain of superconducting patch antenna was 2-4 dB higher than that of Au film antenna.(3) Preparation of YBCO thin film for microwave applications by a plasma coupled magnetron sputtering.We fabricated the YBCO thin films for superconducting antenna by a plasma coupled magnetron sputtering. The Tc and Jc of these films obtained were 87K and 4 x 10^6A/cm^2 at 77K,respectively.(4) Study on a log-periodic antenna operated in millimeter and sub-millimeter wave regionWe designed and fabricated the log-periodic antenna for millimeter and sub-millimeter weve region. We confirmed that the antenna was operated up to 40 GHz. The gain was approximately the same with that of a patch antenna.