AUTORFPOWER software has been developed for automatic RF power measurement at microwave frequencies. In this study, the capabilities of AUTORFPOWER are explained and compared with commercial alternatives. The advantages of the developed software to metrological works and its contributions to future metrological R&D are discussed.

Radio Frequency (RF) power sensor calibration is one of the essential measurements in RF and microwave metrology. For a reliable and accurate power sensor calibration, there are various methods, such as the substitution method, the direct comparison transfer method (DCTM), and the vector network analyzer (VNA)-based calibration method (VBCM). The VBCM is a method that is derived from the DCTM. It is a preferred method since the VNA has a better measurement capability and has fewer connection requirements for measurement devices. In this study, the milestones and potential application errors of the VBCM are given by considering the connection mistakes, measurement faults, calculation errors, and control software coding problems. At the end of the power sensor calibration measurements with the VBCM, the model function components and the uncertainty calculation examples according to the GUM Bayesian method are also presented in this study. In addition, the advantages and disadvantages of the VBCM compared to the former methods are discussed in this study.

RF power measurement is essential in RF and microwave metrology. For reliable and accurate power measurement, automatic measurement is preferred. A software application in C#, named AutoRFPower, was developed for automatic RF power measurement and uncertainty calculations at this study. According to the GUM document, this application is enhanced for uncertainty calculations by utilizing the Law of Propagation method and the Monte Carlo Simulation method. Trial measurements were performed at different RF power levels and frequencies between 50 MHz and 18 GHz using the AutoRFPower software. Law of Propagation and Monte Carlo Simulation uncertainty calculations were carried out by AutoRFPower based on the trial measurements and by the Oracle Crystal Ball simulation application. All measurements and their uncertainty calculations were compared with each other, and this study validated the uncertainty calculation of AutoRFPower. In addition, it was observed that in the Monte Carlo Simulation, uncertainty calculation results were non-symmetrical normal distribution, contrary to the assumption of symmetrical normal distribution according to the Low of Propagation method. Moreover, it has been observed that the statistical distribution of uncertainty changes depending on the dominant component of the parameters in the model function used for the uncertainty calculation with the Monte Carlo Simulation method.

Mobil telefonların Özgül Soğurma Oranı (Specific Absorption Rate) değerinin belirlenmesi için yapılan ölçümler öncesinde ölçüm düzeneğinin doğrulanması gerekir. SAR ölçümlerinde kullanılan robotun, elektrik alan probunun, eşdeğer doku sıvısının ve ölçme programının bir arada doğru olarak çalıştığını kontrol etmek için doğrulama çalışması yapılır. Doğrulama ölçümlerinde, kutu fantomun alt kısmına referans bir dipol anten yerleştirilir. Böylece eşdeğer sıvı üzerine değeri bilinen bir güç uygulanarak sıvı içerisinde elektrik alan oluşması sağlanır. Bu çalışmada doğrulama ölçümlerinin önemli bileşenlerinden biri olan dipol anten yapımı, karakterizasyonu ve doğrulama ölçümlerinden bahsedilecektir

The reflection coefficient measurement of the RF signal generator output is clear when the signal generator output is turned off, as no interfering signal is present. However, measuring the reflection coefficient while the signal generator output is turned on creates complexity, as the generator’s output power can interfere with the reflected signal. A vector network analyzer (VNA) is the reference instrument for measuring the reflection coefficient, capturing both the magnitude and phase of scattering parameters. For measuring the active output of a signal generator, the signals created by the generator and the VNA must be isolated to prevent signal mixing and interference. This paper proposes a unique method to measure the output reflection coefficient of an RF signal generator when the output is on, using a VNA configured for one port reflection coefficient measurement. The method involves tuning the VNA receiver to a frequency slightly offset to the generator’s output. Simultaneously, selecting a narrow intermediate frequency bandwidth (IFBW) reduces the receiver’s noise floor and also eliminates out-of-band interference. As a result, the VNA and the generator operate in different frequency bands to avoid interferences between them, enabling accurate magnitude and phase measurements. To automate the process, a Windows-based software has been developed. This software automates the measurement sequence, controls generator power levels and VNA sweep parameters, captures both the magnitude and phase of the reflection coefficient, and records the result data. It also supports measurement at different output power levels, enabling characterization across a wide range of operating conditions.

An interlaboratory comparison of RF power measurements using automatic power measurement software was carried out among partners of the European Partnership on Metrology project titled “Development of RF and microwave metrology capability II” (RFMicrowave2). The absolute RF power output of a travelling signal generator was measured at six frequencies between 2 GHz and 18 GHz and at three nominal power levels of −10 dBm, 0 dBm, and 10 dBm. Comparison results were evaluated in terms of comparison reference values, degrees of equivalence, and normalised errors. Uncertainty evaluations were performed using both the Guide to the Expression of Uncertainty in Measurement and Monte Carlo simulation methods. The results demonstrate an acceptable level of agreement among participating laboratories and confirm the applicability of automatic power measurement software for interlaboratory RF power comparisons.