In this work, we study the development of a coplanar waveguide (CPW) resonator and its use in an electron spin resonance (ESR) spectrometer. The CPW resonator is designed to operate in S-band (2-4 GHz), with a short circuit configuration leading to miniaturization. It is so constructed such that it has a characteristic impedance of 50 ohms. The resonator supports quasi-TEM mode of propagation owing to its uniplanar nature, demanding detailed electromagnetic simulation. The design parameters and the electromagnetic field distribution are obtained from the simulation. The resonator is fabricated using optical lithography with a rapid prototyping technique. The characteristic response of the resonator is measured by coupling it to a Vector Network Analyzer (VNA). The ESR absorption spectrum of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) is captured by using this resonator in reflection geometry. The microwave magnetic field distribution at the sample position is investigated. The ascertained value of Lande g-factor is consistent with that reported in the literature. Spin sensitivity of the order of 10¹⁵ spins/gauss is achieved upon using this resonator at room temperature. The quality factor of this resonator is found to be low and this makes it suitable for use in a Pulsed ESR spectrometer.

在这项工作中，我们研究了共面波导（CPW）谐振器的开发及其在电子自旋谐振（ESR）光谱仪中的使用。CPW谐振器设计为在S波段（2-4 GHz）下工作，并具有短路结构，可实现小型化。如此构造以使其具有50欧姆的特性阻抗。由于其单平面性质，谐振器支持准TEM传播模式，需要详细的电磁仿真。通过仿真获得了设计参数和电磁场分布。使用具有快速原型技术的光刻技术制造谐振器。谐振器的特性响应是通过将其耦合到矢量网络分析仪（VNA）来测量的。自由基2的ESR吸收光谱 通过使用该共振器以反射几何形状捕获2-二苯基-1-吡啶并肼基（DPPH）。研究了样品位置处的微波磁场分布。兰德g因子的确定值与文献报道的一致。自旋灵敏度为10在室温下使用该谐振器可获得^15个自旋/高斯。发现该谐振器的品质因数较低，因此使其适合用于脉冲式ESR光谱仪。