Stable Factorization of Strictly Hurwitz Polynomials

We propose a stable factorization procedure to generate a strictly Hurwitz polynomial from a given strictly positive even polynomial. This problem typically arises in applications involving real frequency techniques. The proposed method does not require any root finding algorithm. Rather, the factorization process is directly carried out to find the solution of a set of quadratic equations in multiple variables employing Newton’s method. The selection of the starting point for the iterations is not arbitrary, and involves interrelations among the coefficients of the set of solution polynomials differing only in the signs of their roots. It is hoped that this factorization technique will provide a motivation to perform the factorization of two-variable positive function to generate scattering Hurwitz polynomials in two variables for which root finding methods are not applicable

10W GaN PA for 5G NR n78 Band Utilizing RFT Parametric Approach

The focus of this paper is to design the input and output matching networks of a power amplifier to achieve broadband and high efficiency performance which is mandatory for 5G NR operations. The Real Frequency Technique - RFT has been utilized in the design for the synthesis of broadband matching networks which is good for broadband matching. A 10-Watt, 3.2-3.9GHz power amplifier is designed that covers the 5G NR n78 (C-Band, 3.3-3.8GHz) spectrum. The input matching network and output matching network are extracted using the RFT parametric approach employing lumped components. Then, the lumped elements are converted into distributed elements using microstrip line inductance and capacitance equivalences. Once the networks are designed, the power amplifier (PA) stage is completed with the inclusion of bias feeds, and performance is validated. Finally, the PA layout has been obtained for fabrication

A Numerical Procedure to Determine the Power Intake/Delivery Capacity of a GaN RF Power Transistor over Broadband

In this paper, a novel “Real Frequency Line Segment Technique” based numerical procedure is introduced to assess the gain-bandwidth limitations of the given source and load impedances, which in turn results in the ultimate RF-power intake/delivering performance of the amplifier. During the numerical performance assessments process, a robust tool called “Virtual Gain Optimization” is presented. Finally, a new definition called “Power-Performance-Product” is introduced to measure the quality of an active device. Examples are presented to assess the gain-bandwidth limitations of the given source and load pull impedances for the 45W-GaN power transistor of Wolfspeed “CG2H40045” over 0.8 -3.8 GHz bandwidth

Modem techniques to design wide band power transfer networks and microwave amplifiers on silicon RF Chips

RF performance of 0.18 mu m SI processing technology is Investigated via designing a single stage microwave amplifier employing the modern design method called "Simplified Real Frequency Technique (SRFT)". It Is demonstrated 0.18 mu m SI processing technology can be utilized to design ultra wideband amplifiers over the frequency band of 11.2 GHz to 22.3 GHz

Design of Broadband Microwave Power Amplifiers via Fettweis Representation of Brune Functions

In this paper, an X-Band power amplifier prototype is designed over the frequency band of 8 GHz-10 GHz with mixed lumped and distributed elements using so called "Yarman and Fettweis Double Matching-Parametric Approach" and "Design with Mixed Elements Technique' developed by Yarman, Aksen and Fettweis. The proposed algorithms employ three major steps. In the first step, lumped element prototype is generated employing the Fettweis representation of Brune functions. In the second step, lumped element prototype is replaced with its almost equivalent mixed element counterpart. In the last one, electric performance of the overall mixed element amplifier is re-optimized for the maximum power output and the flat transducer power gain. In the course of amplifier design, Cree's 70W GaN HEMT transistor CGHV1J070D is utilized. It is shown that the mixed element power amplifier is capable of delivering 50 W continuous power with 50% power added efficiency over the frequency band of 8 GHz-10 GHz

Design of an Ultra-Wideband GaN Power Amplifier via Real Frequency Technique

This study covers the design steps of a power amplifier prototype which is designed regarding maximum gain and efficiency levels in an ultra-wide bandwidth using real frequency technique. The designed prototype operates from near DC frequencies up to 3 GHz with around 13.5 dB power gain and delivers approximately 40.5 dBm or 11 Watts of power. The power added efficiency of the device varies between 53% to 72% in the wide operation bandwidth. CGH40010F GaN HEMT device of Wolfspeed-Cree Company is used in the design. The design based on the real frequency matching technique using pulled source and load impedance data of the active device. Using appropriate source and load impedances obtained for the optimum gain and efficiency levels, lumped element prototype is generated employing impedance based real frequency single matching technique. Some of the lumped elements are replaced with their distributed counterparts, the rest are replaced with real element models to simulate parasitic effects and loss of real components more reliably. Finally, overall performance of the system is reoptimized, successful results are obtained and presented

Impact of the External Co-channel Interferences Over Multiuser Bi-directional Wireless Relaying Networks-Part I: System Description and Outage Analysis

This paper investigates the impact of co-channel interferences (CCIs) caused by the external terminals over multiuser bi-directional amplify-and-forward (AF) relaying. The investigation considers multiuser pair and single bi-directional AF based relay and finite numbers of external interference terminals in the system model. Simultaneous transmission model, which is default mode, creates CCIs that is caused by the other user-pairs (internal terminals) in the system model. The opportunistic source-pair selection (OSPS) strategy achieves near-optimal solution for the internal CCIs challenge and also achieves diversity order in high SNR regimes. However, external terminals' CCIs are inevitable and degrades the system performance. The main aim of this paper is to clearly state the impacts of external CCIs both for simultaneous and OSPS methods. According to the simulation results, in the case that the external terminals' transmit powers are identical and non-identical to each other, and if the external terminals' transmit powers are proportional with SNR, this results on the degradation of the achievable diversity order from to 0 while also affecting the coding gain. The results also show that, when the external terminals have fixed transmit power values rather than proportional with SNR, in this circumstance, external terminals interference does not affect the achievable diversity order but it affects the system coding gain.The results also show that, when the number of external terminals which affect the user-pairs and relay terminals increase, for both identical and non-identical cases, the losses at the system coding gain exponentially decay. On the other hand, if the external terminals have non-identical transmit powers and if the relay terminal is interfered with more transmit power in comparison with what interferes with the user-pairs, this gives better performance values

Design of broadband microwave amplifiers with mixed-elements via reflectance data modeling

A practical method is introduced, to design single-stage broadband microwave amplifiers with mixed lumped and distributed elements via modeling the reflectance data obtained from lumped-element input and output matching network prototypes. The same transducer power gain level is obtained by using less number of lumped-elements in the mixed-element amplifier than that of the lumped-element amplifier prototype. A mixed-element amplifier design is presented, to exhibit the utilization of the method. It is expected that the method will be employed, to design microwave amplifiers for broadband communication systems. (C) 2007 Elsevier GmbH. All rights reserved

Design of mixed-element networks via modeling

A new method is introduced, to design mixed lumped and distributed element network; via modeling the data obtained from the driving point input reflectance of a lumped-element prototype. A mixed-element Chebyshev filter design is presented, to exhibit the utilization of the new method. It is expected that the new method will be employed, to design wideband communication networks manufactured using VLSI technology