Radiation Assessment of Quadrature LC Oscillators

This chapter presents a comprehensive assessment of the ionizing radiation-induced effects on the performance of quadrature phase LC-tank-based VCOs. Two different QVCOs capable of generating frequencies in the range of 2.5–2.9 GHz are implemented in a commercial 65 nm CMOS technology to target harsh radiation environments like space applications and HEP experiments. The architectures are based on the popular implementation of parallel-coupled and super-harmonic coupled QVCOs. The various performance metrics (oscillation frequency, quadrature phase, phase noise, frequency tuning range, and power consumption) of the two different QVCOs are evaluated with respect to a TID up to a level of approximately 100 Mrad (SiO \(_2\) ) through X-ray irradiation. During irradiation, the electrical characterization of the prototype samples is performed under the biased condition at room temperature. The test setup of the TID experiment is discussed, and the results obtained are statistically analyzed in this chapter to perform a comparative study of the performance of the two different QVCOs and evaluate the effectiveness of the RHBD techniques employed in the implementations. The rest of the chapter is arranged as follows: Sect. 4.1 presents the prior art. Section 4.2 discusses the implementation of the QVCOs in detail. The test setup for X-ray irradiation is elaborated in Sect. 4.3 with a detailed description of the experimental results and a comparison of the performance study of the two different QVCOs. Section 4.4 concludes the chapter with a summary of the TID sensitivity study on the two QVCOs.