A Sub-Terahertz Near-Field Subwavelength Sensor Element with Micrometer Spatial Resolution Fed by A Goubau Line

This paper presents a Sub-terahertz (Sub-THz) super-resolution near-field imaging sensor with micrometer spatial resolution. The sensor consists of two split-ring resonators (SRRs) to achieve a subwavelength spatial resonance, a metal slot as a near-filed sensing area fed by the two SRRs resonators, and two metal supporting arms connecting the SRR and the metal slot. The metal slot with width of 2 um forms a near-field ultra-resolution radiation and sensing structure. In order to achieve low transmission loss, the Goubau metal line is employed to feed the near-field sensor. Numerical simulation shows that the subwavelength near-filed sensor owns a spatial resolution of about 10 um at the operating frequency 0.3 THz, which is 1/100 wavelength spatial. The effective operating range between the sensor and the object under test is about 2 um. Besides, the proposed near-field sensor also shows low insertion loss and high dynamic range that are 1.6 dB and 10 dB, respectively.