325 MHz solid state RF amplifier development at BARC under IIFC - PowerPoint PPT Presentation

325 MHz solid state RF amplifier development at BARC under IIFC Manjiri Pande and Team RFSS, IADD BARC

Outline 1. RF devices 2. Solid State RF Amplifier topology 3. 3. Solid State RF Amplifier (@ 325 MHz) development under IIFC Solid State RF Amplifier (@ 325 MHz) development under IIFC 4. Schedule IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

Available RF Technologies February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

4 February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

Solid State RF Amplifiers The advantages of solid state amplifier � No High Voltage and Vacuum requirement � No filament, no warm up time and simple start up procedures � High Reliability � Modular Design � Graceful Degradation � Easy and Fast Maintenance � Better RF signal (Harmonics, Phase Noise etc.) � Overall moderate Cost � Overall moderate Cost Expected decrease in Price/Watt and Size/Watt due to world-wide R&D efforts Solid State RF Power Amplifier Development at 325 MHz Solid State RF Power Amplifier Development at 325 MHz � MOSFET based RF power modules � Input RF power is divided into ‘n’ parts (1:n) � ‘n’ no. of individual RF modules amplifies the power � The output power from these ‘n’ modules is combined (n:1) to get higher power � The high efficiency RF amplifier modules of 1 kW have been developed � Technology of Power Dividers Combiners (PDC) at various power levels February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

Solid State Amplifier: The basic Building blocks Output RF power of individual solid state device is medium, maximum up to 1200 Output RF power of individual solid state device is medium, maximum up to 1200 Watts. Hence higher power level of the order of few kW level can be obtained by Watts. Hence higher power level of the order of few kW level can be obtained by summing output of multiple power modules using power combiners. Different summing output of multiple power modules using power combiners. Different constituent blocks which need to be developed separately, are as shown constituent blocks which need to be developed separately, are as shown February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC 6

Architecture of SSRFPA Due to divide and The variation in phase and amplitude combine strategy, the of amplifier modules demands for PA n design of each part is proper summation at combiners that equally important leads to good combining efficiency. n n PA Control combiner Signal r splitter Directional RF power com Power spl coupler coupler Load Load RF RF Driver PA signal Switch 1 1 PA 1 Interlock and Protection Water cooling Compact DC supplies IIFC meeting- 325 MHz RF- manjiri - IADD-BARC February 27, 2015

Indian Institute and Fermi Lab Collaboration (IIFC Indian Institute and Fermi Lab Collaboration (IIFC) ) • Deliverables under the collaboration and under Addendum V � 1 � 1 kW, 325 MHz, solid state power amplifier (SSPA) – Completed � 1 kW, 325 MHz, solid state power amplifier (SSPA) – Completed � 3 kW, 325 MHz, solid state power amplifier (SSPA) – Completed and delivered � 7 kW, 325 MHz, solid state power amplifier (SSPA) – Bench tested W, 325 MHz, solid state power amplifier (SSPA) – Bench tested. • In the next phase, 30 numbers of 10 kW, 325 MHz, solid state power amplifier (SSPA) need to be developed under IIFC Status: Design completed February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC 8

R &D done for RF power modules and power dividers/ combiners R &D done for RF power modules and power dividers/ combiners Our aim was and is , to design and develop 1) the high efficiency (RF) power modules 2) Power dividers / combiners (PDC) with good matching 3) Directional couplers for RF power measurement and and 1) Use compact DC supplies 2) Use reliable interlock and protection for safe operation of RFPA 3) Achieve excellent efficiency and power gain of the amplifier Started with technology development of the most important basic building blocks of Started with technology development of the most important basic building blocks of SSPA, i.e. 1) High efficiency RF amplifier power modules (1 kW) and 2) Power combiner /divider technology at various power levels A 325 MHz, 1 kW - Amplifier module was designed. Substantial investigation was done using different laminates based on their properties like dielectric strength, thermal conductivity etc. During development period, modules were developed using three types of printed circuit boards (pcb) material (laminates) as, a) FR4 b) Ceramic filled PTFE c) Glass microfiber reinforced PTFE 9 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC February 27, 2015

Comparison of Specifications Glass microfiber Ceramic filled Fermi Lab FR4 Main Specifications reinforced PTFE PTFE specs (BARC) (BARC) (BARC) Center 325 325 325 325 frequency (MHz) Power output (W) 1000 800 (long term) 1000 >1000 (single module) (short term) 1000 (short term) >60 > 60 > 60 Power Gain (dB) 60 ( individual ( individual module: ( individual (Overall) module19.3) module19.3) 21.8) 21.8) module: 22.8) module: 22.8) Efficiency(AC/RF) (%) > 60 < 60% 62 > 63 (module) Issues if any Thermal issue Thermal issue No issues Adopted for 1, 3, 7 and Status Discontinued Discontinued 10 kW amplifiers Thermal/Heat transfer -- Poor Good V. Good efficiency February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

R&D and development RF Power Amplifier Modules The PA PA module module is the main building building block block. It determines the system linearity, efficiency and power consumption. Its design at high power, involves study of issues like RF transistor selection, device model, device efficiency, operating modes and device parasitic effect . Center Frequency : 350, 352 , 325 MHz Power output (sat.) : 100 W, 300 W, 800 W, 1000W Power Gain : 8.5-20 dB Power Gain : 8.5-20 dB Efficiency : 50 - 68% Protection : Circulator Load O/p Balun I/P I/p Balun Device Circulator O/P 250W Amplifier module February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

R&D and development RF Power Amplifier Modules 300W Amplifier module at 352 MHz 800W Amplifier module on 1kW Amplifier module at 325 MHz FR4 laminate IIFC meeting- 325 MHz RF- manjiri - IADD-BARC February 27, 2015

R&D and development of Power Dividers /Combiners • Combiners designed using pcb and coaxial lines. • 2, 4, 8-way combiners • Power levels 100 W, 1 kW, 10 kW. • Return loss of >20dB at input ports (with phase coherence) • Return loss of better than 25dB at output port. • Isolation among input ports better than 25dB. • Transmission loss < 0.15dB 2-way combiner 4- way pcb based 4- way, 3 kW coaxial Combiner/splitter Combiner/splitter 2-way splitter February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

Power Dividers /Combiners - - continued 8 way, pcb based Combiner/splitter Combiner/splitter 5 kW, 8 way, coaxial 8 kW, 8 way, coaxial Combiner/splitter @ Combiner/splitter @ 325 MHz 352 MHz 10 kW, 2-way, coaxial Combiner/splitter 4 kW, 8 way, coaxial Combiner/splitter February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

Directional Coupler: Design and development Simulated directional Directional coupler 1 kW Directional coupler 500 coupler 3 kW at 325 MHz at 325 MHz Watt at 325 MHz Watt at 325 MHz Parameters Results with low RF signal (dB) Isolation -72 Coupling - 44.4 Directivity 27.6 Directional coupler 3 kW @ 325 MHz with BW of 30 MHz February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC Manjiri/IADD/BARC/V- IIFC meet

Contribution under IIFC: Solid State RF amplifiers at 325 MHz All are stand alone RF amplifiers and are designed and developed indigenously 1 kW Amplifier 7 kW Amplifier 3 kW Amplifier • Power: 3 kW • Power: 7 kW Power: 1 kW • • Overall Gain: > 65 dB • Overall Gain: > 90 dB • Overall Gain: > 65dB • Efficiency : 65 % • Efficiency : 66.3 % • Efficiency : 61 % 2 nd Harmonics: - 41.9 dB 2 nd Harmonics: -41.9 dB 2 nd Harmonics: - 41.5 dB • • • February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC 16

This 3 kW @ 325 MHz work has been published in: Journal: Nuclear Instruments and Methods in Physics Research A 735(2014) 283–290 Title: Development of 3kW, 325MHz solid-state RF power amplifier using four power amplifier modules Authors: B.V. Ramarao , S Sonal, J. K. Mishra , M. Pande, P. Singh, G Kumar, J. Mukherji February 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

7 kW, 325 MHz SSRFPA Power Power Meter Meter 200 W 200 W 1-5/8” line 10 kW NRT-Z44 Load NRT-Z44 Power Meter 1:8 8:1 Divider Combiner 50 W SSPA Sig. Generator DC 50V, 30A Water each cooling (8) Feb 27,2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

7 kW, 325 MHz RF amplifier Assembled and tested unit of 7 kW SSRFPA Interlock card under development Feb 27, 2015 IIFC meeting- 325 MHz RF- manjiri - IADD-BARC

7 kW, 325 MHz SSRFPA Display of Calorimetric RF Power measurement of Waveform RF Power at 7 kW on spectrum analyzer Sensor data of Calorimetric measurement of RF Power IIFC meeting- 325 MHz RF- manjiri - IADD-BARC