Development of 5G networks requires a substantial increase to both spectral and power efficiency of transmitters. It is known that these two parameters are subjected to a mutual trade-off. To increase the linearity without losing power efficiency, linearization techniques are applied to power amplifiers. This paper aims to compare most popular linearization techniques to date and evaluate their applicability to upcoming 5G networks. The history of each respective linearization technique is followed by the main principle of operation, revealing advantages and disadvantages supported by concluding the latest research results. Three main groups of linearization methods currently known are feedforward, feedback, and predistortion, each with its own tradeoffs. Although digital predistortion seems to be the go-to method currently, other techniques with less research attention are still non-obsolete. A generalized discussion and a direct comparison of techniques analyzed are presented at the end of this paper. The article offers a systematic view on PA linearization problems which should be useful to researchers of this field. It is concluded that there are still a lot of problems that need to be addressed in every linearization technique in order to achieve 5G specifications.

Digital oscilloscope’s structure has analog signal acquisition circuit, which transforms signal’s amplitude to fit ADC dynamic range. This circuit is commonly called oscilloscope’s vertical or front-end amplifier. Difficulty in designing front-end amplifiers in GHz range largely affects higher frequency range oscilloscope’s price. This work is focused on designing a front-end amplifier using discrete and openly sold components. We propose a design for attenuator, buffer, variable gain circuits. Amplifier’s prototype is designed. Main characteristics of the amplifier were measured. Measured bandwidth is 3 GHz. Amplifier’s gain and attenuation can support vertical scale sensitivity range from 10 mV/div to 1 V/div. Step response distortion is under 10 %. SMD and PTH relay model attenuators were evaluated. In this paper we review oscilloscope’s front-end purpose and structure. We review amplifiers design and provide the results of experimental measurements.

Power amplifier behavioral modeling is an important technique for efficient and accurate digital predistortion, but conventional models fail to generalize when applied across varying carrier frequencies. This work addresses the carrier-frequency generalization by proposing a parameterized memory polynomial (PMP) modeling approach. The method involves extracting memory polynomial models at multiple carrier frequencies and interpolating their coefficients using spline interpolation, resulting in a single model capable of operating across a wide carrier-frequency band. Experimental validation was conducted using measured input–output PA responses over the 3.3–3.8 GHz range. Results obtained show that PMP built on three carrier frequencies achieves up to 9 dB average NMSE improvement compared to the fixed-coefficient MP model. The proposed model nearly matches the accuracy of the MP model at the entire measured range. The overall accuracy depends on the combination of the introduced interpolation error and the discrepancy between the initial MP model fitting errors. The proposed method offers a practical solution for PA modeling in systems requiring fast frequency agility, such as carrier aggregation and dynamic spectrum access, eliminating the need for model retraining at each operating frequency.