23 research outputs found
Energy Efficient RF for UDNs
No full textMulti-standard RF front-end is a critical part of legacy and future emerging mobile architectures, where the size, the efficiency, and the integration of the elements in the RF front-end will affect the network key performance indicators (KPIs). This chapter discusses power amplifier design for both handset and base station applications for 5G and beyond. Also, this chapter deals with filter-antenna design for 5G applications that include a synthesis-based approach, differentially driven reconfigurable planar filter-antenna, and an insensitive phased array antenna with air-filled slot-loop resonators
Highly Efficient Wideband Harmonic-Tuned Power Amplifier Using Low-pass Matching Network
No full textThis paper presents a design approach for a broadband and high efficiency harmonic-tuned power amplifier (PA) based on a low-pass filtering (LPF) matching network (MN). The MN is composed of quasi-lumped open stubs (λg/8 λg/4). Compared with widely used conventional Chebyshev LPF matching networks, the proposed output matching network provides a good approximation of desired lumped elements over the entire frequency band. The MN offers a sharp roll-off to the transition band. Optimum fundamental and second harmonic load impedances are obtained by identifying the high efficiency regions on the reactance plane for second harmonic band placement, the design is reduced to a fundamental matching problem. A PA with this concept is designed from 1.0 to 1.5 GHz (FBW=40%) using a Cree GaN HEMT CGH40045. The peak output power, drain efficiency, and gain are 47.3 dBm, 80%, and 12.6 dB, respectively at 1.2 GHz. Furthermore, the PA is evaluated using a COFDM signal with an average output power of 40 dBm, a peak-to-average ratio (PAPR) of 10 dB, and a bandwidth of 2.5 MHz. The PA can achieve a peak drain efficiency of 49% and the adjacent channel power ratio (ACPR) of-26.3 dBc at 1.3 and 1 GHz
Techno-economic optimisation of battery storage for grid-level energy services using curtailed energy from wind
No full textThe increasing integration of renewable energy sources makes balancing an electricity grid challenging due to their intermittency. Renewable energy can be curtailed especially when production exceeds demand or when there are transmission and/or distribution network congestions within a grid. However, curtailment would become unnecessary with battery storage, provided the battery storage has enough available storage capacity, which can store energy during the time of excess generation and in turn discharge it to the grid once the demand is high during peak times. Hence, stored energy from batteries can potentially offset supply from expensive and environmentally harmful peak plants e.g. open/combined cycle gas turbine. We investigated the techno-economic prospects of the utilisation of curtailed energy from the wind with bulk battery storage to replace open and combined cycle gas turbine power plants, by taking the UK as a case study. A techno-economic model to size and optimise a Li-ion type battery was developed. The optimisation aimed to determine at what cost and size the storage can be commercially viable for grid-level energy applications. Results show that under base case assumptions of a 15% day to day curtailment from wind and £200/kWh battery cost, an optimised battery size of 1.25 GWh could supply 285 GWh peak demand per annum and its corresponding net present value of £22.4m, internal rate of return of 1.7% and a payback period of 14 years could be achieved. However, to achieve the internal rate of return of 8%, a minimum hurdle rate for investment, the cost of battery would need to be below £150/kWh. Sensitivity analysis with parameters such as curtailed wind, depth of discharge, battery efficiency, and cost and income of battery shows that all techno-economic parameters considered in this research have a significant impact on the commercial viability of battery storage for grid applications
A 70-W Asymmetrical Doherty Power Amplifier for 5G Base Stations
No full textYesMuch attention has been paid to making 5G developments more en-ergy efficient, especially in view of the need for using high data rates with more complex modulation schemes within a limited bandwidth. The concept of the Doherty power amplifier for improving amplifier efficiency is explained in addi-tion to a case study of a 70W asymmetrical Doherty power Amplifier using two GaN HEMTs transistors with peak power ratings of 45W and 25W. The rationale for this choice of power ratio is discussed. The designed circuit works in the 3.4GHz frequency band with 200 MHz bandwidth. Rogers RO4350B substrate with dielectric constant εr=4.66 and thickness 0.035 mm is used. The perfor-mance analysis of the Doherty power amplifier is simulated using AWR MWO software. The simulated results showed that 54-64% drain efficiency has been achieved at 8 dB back-off within the specified bandwidth with an average gain of 10.7 dB
A 70-W Asymmetrical Doherty Power Amplifier for 5G Base Stations
No full textYesMuch attention has been paid to making 5G developments more en-ergy efficient, especially in view of the need for using high data rates with more complex modulation schemes within a limited bandwidth. The concept of the Doherty power amplifier for improving amplifier efficiency is explained in addi-tion to a case study of a 70W asymmetrical Doherty power Amplifier using two GaN HEMTs transistors with peak power ratings of 45W and 25W. The rationale for this choice of power ratio is discussed. The designed circuit works in the 3.4GHz frequency band with 200 MHz bandwidth. Rogers RO4350B substrate with dielectric constant εr=4.66 and thickness 0.035 mm is used. The perfor-mance analysis of the Doherty power amplifier is simulated using AWR MWO software. The simulated results showed that 54-64% drain efficiency has been achieved at 8 dB back-off within the specified bandwidth with an average gain of 10.7 dB
Recent Developments of Dual-Band Doherty Power Amplifiers for Upcoming Mobile Communications Systems
No full textPower amplifiers in modern and future communications should be able to handle different modulation standards at different frequency bands, and in addition, to be compatible with the previous generations. This paper reviews the recent design techniques that have been used to operate dual-band amplifiers and in particular the Doherty amplifiers. Special attention is focused on the design methodologies used for power splitters, phase compensation networks, impedance inverter networks and impedance transformer networks of such power amplifier. The most important materials of the dual-band Doherty amplifier are highlighted and surveyed. The main problems and challenges covering dual-band design concepts are presented and discussed. In addition, improvement techniques to enhance such operations are also exploited. The study shows that the transistor parasitic has a great impact in the design of a dual-band amplifier, and reduction of the transforming ratio of the inverter simplifies the dual-band design. The offset line can be functionally replaced by a Π-network in dual-band design rather than T-network
