APPLICATION NOTE CGH40006S, Low Noise Amplifier Demonstrator Introduction Cree has developed a low noise amplifier circuit using a Cree CGH40006S GaN HEMT transistor as a means of demonstrating the wide bandwidth low noise performance and ruggedness of the device. This application note describes the typical performance that has been achieved and that which can be expected when evaluating the demonstrators. Details of the circuit are included for further understanding of the topology and all necessary information has been provided to aid reproduction of the amplifier. Features • Demonstrator of performance over 225 MHz - 2.0 GHz • 17 dB Small Signal Gain • >50 % Power Added Efficiency • <3 dB Noise Figure • 45 dBm Third Order Intercept -013 ote: APPNOTE Application N Rev. A • Intended to be used with C-IED, MilComm, Instrumentation applications PN: CGH40006S-LNA-KIT Subject to change without notice. www.cree.com 1 Basic Amplifier Specification Maximum Ratings for Evaluation of Demonstrator at 25°C Parameter Gate-to-Source Voltage Frequency Minimum Maximum Units -10 +2 Volts 0.225 2 GHz Notes Input Power Level - 39 dBm Input Power Level - 42 dBm CW Device Failure Input Power Level - 44 dBm Pulsed 300µs 10% Duty Cycle No Degradation Input Power Level - 46 dBm Pulsed 300µs 10% Duty Cycle Device Failure Operating Junction Temperature - 175 ˚C -40 +150 ˚C Case Temperature CW No Degradation Summary of Typical Low Noise Amplifier Demonstrator Performance Frequency Characteristics Units 225 MHz 500 MHz 1000 MHz 2000 MHz Small Signal Gain 18.5 18.0 17.0 17.5 dB Input Return Loss -12.5 -9 -7 -6 dB 13.7 13.5 13.2 12.8 dB Power Added Efficiency PIN = 25 dBm 57.5 57.0 50.0 40.0 % Noise Figure 1.75 2.1 2.5 3.15 dB Power Gain PIN =25 dBm Note 1: IDQ = 50 mA Note 2: Individual device characteristics are as per CGH40006S data sheet Note 3: VGS has been selected for best noise figure / efficiency tradeoff Typical Circuit Bias Conditions Circuit Element Bias Voltage Quiescent Bias Circuit Gate Bias -3.0 50 mA Drain Voltage +28 NOTE: GATE BIAS MUST BE APPLIED BEFORE THE DRAIN BIAS IS ACTIVATED. Copyright © 2011-2012 Cree, Inc. All rights reserved. Permission is given to reproduce this document provided the entire document (including this copyright notice) is duplicated. The information in this document is subject to change without notice. Cree and the Cree logo are registered trademarks of Cree, Inc. Other trademarks, product and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. Cree Confidential and Supplied under terms of the Mutual NDA. 2 APPNOTE-013 Rev. 9 Cree, Inc. 4600 Silicon Drive Durham, North Carolina USA 27703 USA Tel: +1.919.313.5300 Fax: +1.919.869.2733 www.cree.com/wireless CGH40006S LNA Circuit Typical Sparameters Details of the CGH40006S Demonstrator Circuit Vdd = 28 V, Idq = 50 mA 30 20 10 Magnitude (dB) 0 -10 -20 -30 -40 S(2,1) -50 S(1,1) S(2,2) -60 -70 0 500 1000 1500 2000 2500 3000 Frequency (MHz) Figure 1 -CGH40006S LNA Circuit Typical S-parameters VDD = 28 V, IDQ = 50 mA CGH40006S LNA Noise Figure vs Frequency 5.0 4.5 4.0 Noise Figure (dB) 3.5 3.0 2.5 2.0 1.5 Measured 1.0 Simulated 0.5 0.0 0 500 1000 1500 2000 2500 3000 Frequency (MHz) Figure 2 -CGH40006S LNA Noise Figure vs Frequency Copyright © 2011-2012 Cree, Inc. All rights reserved. Permission is given to reproduce this document provided the entire document (including this copyright notice) is duplicated. The information in this document is subject to change without notice. Cree and the Cree logo are registered trademarks of Cree, Inc. Other trademarks, product and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. Cree Confidential and Supplied under terms of the Mutual NDA. 3 APPNOTE-013 Rev. 9 Cree, Inc. 4600 Silicon Drive Durham, North Carolina USA 27703 USA Tel: +1.919.313.5300 Fax: +1.919.869.2733 www.cree.com/wireless Details of the CGH40006S Demonstrator Circuit CGH40006 LNA Circuit Psat, PAE and Power Gain vs Frequency 16 Gain 70 14 60 12 PAE 50 10 POUT (dBm) 8 40 30 Gain (dB) & Pout (W) Pout (dBm) & PAE (%) 80 6 POUT (W) PAE (%) Pout (dBm) 20 4 Gain (dB) Pout (W) 10 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2 2400 Frequency (MHz) Figure 3 -CGH40006S LNA Circuit PSAT, PAE and Power Gain vs Frequency Copyright © 2011-2012 Cree, Inc. All rights reserved. Permission is given to reproduce this document provided the entire document (including this copyright notice) is duplicated. The information in this document is subject to change without notice. Cree and the Cree logo are registered trademarks of Cree, Inc. Other trademarks, product and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. Cree Confidential and Supplied under terms of the Mutual NDA. 4 APPNOTE-013 Rev. 9 Cree, Inc. 4600 Silicon Drive Durham, North Carolina USA 27703 USA Tel: +1.919.313.5300 Fax: +1.919.869.2733 www.cree.com/wireless Details of the CGH40006S-LNA-KIT Demonstrator Circuit Figure 4 - Schematic of CGH40006S-LNA-KIT Demonstrator Circuit Figure 5 - CGH40006S-LNA-KIT Demonstrator Printed Circuit Board Assembly Copyright © 2011-2012 Cree, Inc. All rights reserved. Permission is given to reproduce this document provided the entire document (including this copyright notice) is duplicated. The information in this document is subject to change without notice. Cree and the Cree logo are registered trademarks of Cree, Inc. Other trademarks, product and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. Cree Confidential and Supplied under terms of the Mutual NDA. 5 APPNOTE-013 Rev. 9 Cree, Inc. 4600 Silicon Drive Durham, North Carolina USA 27703 USA Tel: +1.919.313.5300 Fax: +1.919.869.2733 www.cree.com/wireless Details of the CGH40006S LNA Demonstrator Circuit continued CGH40006S Demonstrator Bill of Materials Reference Designator Description Quantity R1, R3 RES, 1/16W, 0603, 1%, 887 Ohms 2 R2, R5 RES, 1/16W, 0603, 1%, 5.1 Ohms 2 R4 RES, 1/16W, 0603, 1%, 3.3 Ohms 1 R6 RES, 1/16W, 0603, 1%, 432 Ohms 1 CAP, DC BLOCK, MULTI-LAYER, 0603, 850pF 2 C2 CAP, 1.3pF, +/-0.1pF, 0603, ATC 1 C3 CAP, 82.0pF, +/-5%, 0603, ATC 1 C5 CAP 10uF, 16V, TANTALUM 1 C7 CAP, 7.5pF, +/-0.1pF, 0603, ATC 1 C8 CAP, 470pF, 5%, 100V, 0603 1 C9 CAP, 33000pF, 0805, 100V, X7R 1 C10 CAP, 1.0uF, 100V, 10%, X7R, 1210 1 C11 CAP, 33 uF, 20%, G CASE 1 INDUCTOR, SMT, 0603, 270nH, 5%, RoHS COMPLIANT 2 HEADER RT>PLZ .1CEN LK 5POS 1 C1, C6 L1,L2 J1 J2,J3 CONN, SMA, PANEL MOUNT JACK, FLANGE, 4-HOLE, BLUNT POST 2 PCB, RO4350B, 20 MIL THK, CGH40006S 225 MHz - 2 GHz LNA APPLICATION CIRCUIT 1 2-56 SOC HD SCREW 1/4 SS 4 #2 SPLIT LOCKWASHER SS 4 Conclusion This application note has shown the performance advantages of using discrete GaN HEMT transistors for low noise amplifiers. The reference design here shows that it is possible to achieve wide bandwidths, high power and efficiency whilst maintaining low noise and is able to withstand CW input power of 5 W with no degradation. As this transistor is unmatched performance can be replicated at other frequency bands. This reference design was generated with first pass success using Cree’s large signal models, which are available on request. Copyright © 2011-2012 Cree, Inc. All rights reserved. Permission is given to reproduce this document provided the entire document (including this copyright notice) is duplicated. The information in this document is subject to change without notice. Cree and the Cree logo are registered trademarks of Cree, Inc. Other trademarks, product and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. Cree Confidential and Supplied under terms of the Mutual NDA. 6 APPNOTE-013 Rev. 9 Cree, Inc. 4600 Silicon Drive Durham, North Carolina USA 27703 USA Tel: +1.919.313.5300 Fax: +1.919.869.2733 www.cree.com/wireless Cree CGH40006S Low Noise Amplifier Demonstrator Setup Instructions 1. Position the demonstrator amplifier fixture such that the RF source (50Ω) is connected to the left side of the fixture and the RF load (50Ω) is connected to right side of the fixture. 2. Connect the 5-pin bias cable. 3. Verify all power supplies are at 0 volts before turning on. 4. Connect the test fixture RED wires to the drain power supply. 5. Connect the test fixture WHITE wire to the gate power supply. 6. Connect the test fixture BLACK wires to the return (common) terminals of the gate and drain power supplies. 7. Verify connections with the schematic shown in Figure 4. 8. Turn on the gate bias power supply. Adjust the power supply to -5.0 V. 9. Turn on the drain bias power supply. Adjust the power supply to +28 Volts. There should be NO current flow from the power supply. 10. Adjust the current by changing the gate bias supply for a drain current (Idq) of 50mA. 11. Apply low RF drive, 10 dBm (1000 MHz), and verify the fixture has approximately 17 dB of gain. Increase RF drive to the desired output level and verify the performance with the transistor data sheet. 12. To shut down the circuit: Turn off the RF test signal. Turn off the +28 V Drain supplies and lastly turn off the gate voltage supplies. Copyright © 2011-2012 Cree, Inc. All rights reserved. Permission is given to reproduce this document provided the entire document (including this copyright notice) is duplicated. The information in this document is subject to change without notice. Cree and the Cree logo are registered trademarks of Cree, Inc. Other trademarks, product and company names are the property of their respective owners and do not imply specific product and/or vendor endorsement, sponsorship or association. Cree Confidential and Supplied under terms of the Mutual NDA. 7 APPNOTE-013 Rev. 9 Cree, Inc. 4600 Silicon Drive Durham, North Carolina USA 27703 USA Tel: +1.919.313.5300 Fax: +1.919.869.2733 www.cree.com/wireless