On the use of multitone techniques for assessing RF components' intermodulation distortion

Abstract

A comprehensive analysis of various techniques currently used for assessing microwave components' nonlinear distortion behavior is presented in this paper. The output of a third-order system subject to a two-or three-tone input is given, and then used as the comparison reference for studying the response to a general multitone or random excitation. Theoretical results thus obtained allowed the generalization of standard twotone intermodulation (IMD) figures of merit, to multitone IMD ratio, multitone or noise adjacent channel power ratio, and noise power ratio (NPR). This approach proved that normal NPR tests produce optimistic results that can be as large as 7 dB when evaluating in-band co-channel power interference.

Analysis of Power Amplifier Nonlinear Response Based on Practical Circuit Parameters

“…력비(adjacent channel power ratio : ACPR)를 추정하기 위 해 반드시 필요하다 [1]- [2]. 따라서 이에 대한 연구들이 진 행되어 왔으며 특별히 다층 슬라이스 모델(multi-slice behavioral model)을 기반으로 IMD 비대칭 특성을 가지고 있는 전력 증폭기의 비선형 특성에 대해 많은 연구가 이루 어져왔다 [3]- [5].…”

On the effects of memoryless nonlinearities on M-QAM and DQPSK OFDM signals

“…In that case, exploiting the independence of the processes and , we can calculate the resulting noise power per carrier as the product of the variances of the respective noise terms. Assuming a rectangular time window is employed at the OFDM receiver, the variance of in a carrier spacing bandwidth is given by (17) Therefore, the noise power per carrier due to the terms is evaluated as (18) where is the variance of . In order to calculate , we need to express the power of the baseband components generated by .…”

“…Pedro and de Carvalho in [17] have calculated many important IMD figures-of-merit in regard to third-order nonlinear circuits. In [18], Liu presents an approximate SNR evaluation.…”

A Simplified Approach for Quasi-linear Power Amplifier Distortion Evaluation

“…Two cases have been considered here: second-order and fourth-order polynomial expansion in (6). Fig.…”

“…In fact, it involves an input test signal with non-zero bandwidth (amplitude and phase modulation) and in-band distortion products at the output. More recently, even more realistic tests, in the frame of a digitally modulated communication scheme, are considered such as the evaluation of the Adjacent and the Co-Channel Power Ratio [6], [8]. The simulation of all of these non-linearity tests (IMR, ACPR, CCPR,…) usually involves both a very accurate model, taking into account the non-linear dynamic behavior of the power amplifier/electron device, and very sophisticated numerical simulation tools in the framework of Computer Aided Design environments (multi-tone HB, envelope algorithms, etc.)…”