Detailed Design Scheme Research Articles

Development of a Type-N Coaxial Microcalorimeter for RF and Microwave Power Standards at KRISS

This paper introduces a newly constructed type-N coaxial microcalorimeter that will serve as a primary power standard in Korea Research Institute of Standards and Science. The detailed design scheme of the microcalorimeter is presented, and its characteristics are evaluated. The performance of an adiabatic line was simulated with a finite-element-method-based tool and predicted. The measured insertion loss of the assembled adiabatic line was less than 0.15 dB. Frequency and power sweep measurements were performed on a reference standard to find a substituted power level that minimized the dual-element error. We also propose evaluation standards that can be used for the measurement of radio frequency loss. The correction factor for the effective efficiency of the reference standard was experimentally evaluated. We also present an uncertainty evaluation process and the corrected effective efficiency of a type-N coaxial reference standard.

Adiabatic Design for a Coaxial Transmission Line

This paper proposes an air-gap applied adiabatic line for a coaxial transmission line. The adiabatic characteristics with excellent microwave transmission were simulated in terms of the S-parameter and the heat transfer of coaxial lines with a finite-element-method-based tool for the adiabatic microwave design. The detailed design scheme of the air-gap adiabatic line is presented and its performance is evaluated. The adiabatic efficiency associated with microwave feature was analyzed by a resistive equivalent circuit model of the line. We made a stainless steel air-gap adiabatic line that had about 11 times greater thermal resistance than that of a gapless coaxial line, a beryllium copper line, with the increment of just 0.4-dB insertion loss. We also propose a solution to improve the low-frequency transmission of an air-gap adiabatic line with a tunable ground wire for broad-band feature.

Design and derivation of the dual transponder carrier ranging system

The accuracy of microwave ranging is mainly limited by the frequency instability of the oscillator that generates the carrier phase signal. A dual transponder carrier ranging method is used to minimize the oscillator noise by combining the reference and the to-and-fro measurements. This ranging approach together with pseudo-noise ranging or other means can be used to measure the inter-satellite distance with a high precision. The pseudo-noise ranging system or other ranging systems help to solve the integer circles while the dual transponder ranging system guarantees the accurate fractional circle. The two satellites work in the master-slave mode. The range measurements are derived on the master satellite while the slave satellite just coherently transfers the received signal, so that the dual transponder ranging system does not need to rely on the time tagging system to synchronize the two satellites. This study first describes the dual transponder carrier ranging system and shows how the system removes most of the oscillator noise components effectively. Then, a detailed design scheme on the frequency planning of the ranging system is presented and the supporting analysis illustrates the feasibility of this system. Based on the design innovation, a laboratory demonstration system is assembled to verify the realizability of the dual transponder ranging system. The experimental results demonstrate that a high level of accuracy (about 30 μm under laboratory circumstance) can be achieved by the use of the proposed dual transponder carrier ranging system.

Based on the Repetitive Controller for Induction Heating Power Supply

According to the electromagnetic induction heating power supply control system, puts forward a kind of proportion, integral, differential regulator with repetitive controller combined control strategy, in order to improve the heating process of the power supply output quality. Based on this control strategy, gives the repetitive controller each part parameters of the detailed design scheme and proportion, integral and differential controller coefficient; Construction of compensator Q(z) and S(z) , the introduction of zero phase shift Notch function, effectively inhibit PWM-type induction heating power supply output voltage harmonic interference. To carry out the simulation experiment, the results show that the proposed controller can guarantee that the system has better dynamic and static properties, error convergence rate is greatly improved.

Development of a 3.5-mm Coaxial Microcalorimeter for RF and Microwave Power Standards at KRISS

This paper introduces a newly constructed type-N coaxial microcalorimeter that will serve as a primary power standard in Korea Research Institute of Standards and Science. The detailed design scheme of the microcalorimeter is presented, and its characteristics are evaluated. The performance of an adiabatic line was simulated with a finite-element-method-based tool and predicted. The measured insertion loss of the assembled adiabatic line was less than 0.15 dB. Frequency and power sweep measurements were performed on a reference standard to find a substituted power level that minimized the dual-element error. We also propose evaluation standards that can be used for the measurement of radio frequency loss. The correction factor for the effective efficiency of the reference standard was experimentally evaluated. We also present an uncertainty evaluation process and the corrected effective efficiency of a type-N coaxial reference standard.