本論文提出了平面電路饋入波導圓極化器與基板整合波導功率分配器。
在第二章，我們設計了平面電路饋入波導圓極化器，這個設計使用反對稱漸寬型錐形探針饋入，並且結合使用雙脊與雙槽之圓形波導與方形波導，以整合平面電路至波導轉接以及波導圓極化器兩個元件，減少個別製作兩個元件再進行串接的尺寸。我們將圓形波導與方形波導圓極化器，製作在32 mil 的 Rogers® RO4003 基板上，兩者-10 dB 反射係數的頻寬分別為24.6 %與35.1 %，皆能在滿足X-band (8.2 GHz~12.4 GHz)的部分操作頻段，3 dB Axial Ratio 的頻寬分別為12.7 %與30.5 %，909相位移的頻寬分別為14.6 %與9.2 %。
在第三章，我們設計了基板整合波導功率分配器，並且將電路實現在單層Rogers® RO4003基板上。首先，我們使用50-微帶線T-Junction來達成寬頻的反射係數，接著，我們使用低阻抗微帶線T-Junction來縮小電路面積，另外，我們亦使用Wilkinson功率分配器來改善隔離度，其結果如下所示：
使用50-微帶線T-junction的基板整合波導功率分配器，-15 dB反射係數的頻寬為37.9 %，能涵蓋大部分S-band (2.60-3.95 GHz)的頻帶。頻帶內最大穿透係數為-3.24 dB，頻帶內最小隔離度為-6.57 dB。使用低阻抗微帶線T-junction的基板整合波導功率分配器，-15 dB反射係數的頻寬為46.5 %，能涵蓋全部S-band (2.60-3.95 GHz)的頻帶，頻帶內最大穿透係數為-3.24 dB，頻帶內最小隔離度為-5.57 dB，並且其面積遠小與使用50-微帶線T-junction的基板整合波導功率分配器。使用Wilkinson功率分配器的基板整合波導功率分配器，-15 dB反射係數的頻寬為34.7 %，能涵蓋大部分S-band (2.60-3.95 GHz)的頻帶，頻帶內最大穿透係數為-3.27 dB，並且，頻帶內最小隔離度改善為-33.69 dB。為了降低成本，我們改用單層FR4基板來實現以上的功率分配器，其電路的響應與以上電路相似，但是穿透係數會變得比較差，因為FR4基板的板材損耗比較大。

In this thesis, waveguide polarizers fed by the planar transmission line and substrate-integrated waveguide power dividers are proposed. The details of the content are described below.
In Chapter 2, circular waveguide and rectangular waveguide polarizers fed by the planar transmission line are proposed. Since the antisymmetric tapered probe is used to feed the waveguide polarizers with double ridges and slots directly, the planar transmission line to waveguide transition and the polarizer can be integrated directly, reducing the circuit size. The circular waveguide and rectangular waveguide polarizers are implemented on the Rogers® RO4003 substrate of thickness 32 mil. The fractional bandwidths, in which the reflection coefficient is smaller than -10 dB, of these two polarizers are 24.6% and 35.1%, respectively, covering part of the X-band (8.2-12.4 GHz). The bandwidth of 3 dB Axial Ratio are 12.7% and 30.5%, respectively while the 909 phase shift are 14.6% and 9.2%, respectively.
In Chapter 3, several substrate-integrated waveguide power dividers implemented on the single layer Rogers® RO4003 substrate are proposed. First of all, the T-junction implemented with the 50-Ω microstrip line is used to achieve a broadband response of the reflection coefficient. Successively, the T-junction implemented with the low impedance microstrip line is used to reduce the circuit size of the power divider. Besides, the Wilkinson power divider is used to improve the isolation between the output ports of the power divider. The results are shown below.
The substrate-integrated waveguide power divider using the 50- microstrip line T-junction has a -15-dB reflection coefficient bandwidth of 37.9%, covering most bandwidth of the S-band (2.60-3.95 GHz). In this bandwidth, the transmission coefficient is smaller than -3.24 dB and the isolation is larger than -6.57 dB.
The substrate-integrated waveguide power divider using the low impedance microstrip line T-junction has a -15-dB reflection coefficient bandwidth of 46.5%, covering the whole S-band (2.60-3.95 GHz). In this bandwidth, the transmission coefficient is smaller than -3.24 dB and the isolation is larger than -5.57 dB. In addition, the area occupied is much smaller than that of the substrate-integrated waveguide power divider using the 50- microstrip line T-junction.
The substrate-integrated waveguide power divider using the Wilkinson power divider has a -15-dB reflection coefficient bandwidth of 34.7%, covering most bandwidth of the S-band (2.60-3.95 GHz). In this bandwidth, the transmission coefficient is smaller than -3.27 dB and the isolation is enhanced to be than -33.69 dB.
In order to reduce the cost, the single layer FR4 substrate is used to implement the power dividers mentioned above. The performance of the power dividers implemented with the FR4 substrate is similar to the performance of the power dividers implemented with the Rogers® RO4003 substrate except that the transmission coefficient would be deteriorated since the substrate loss of the FR4 substrate is larger than that of the Rogers® RO4003 substrate.

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