MRF174 The RF MOSFET Line 125W, 200MHz Designed primarily for wideband large-signal output and driver stages up to 200 MHz frequency range. Rev. V1 Product Image N-Channel enhancement mode MOSFET Guaranteed performance at 150 MHz, 28 Vdc Output power = 125 W Minimum gain = 9.0 dB Efficiency = 50% (min.) Excellent thermal stability, ideally suited for Class A operation Facilitates manual gain control, ALC and modulation techniques 100% tested for load mismatch at all phase angles with 30:1 VSWR Low noise figure -- 3.0 dB typ. at 2.0 A, 150 MHz CASE 211-11, STYLE 2 1 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz Rev. V1 2 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz Rev. V1 3 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz Rev. V1 4 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz Rev. V1 5 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz Rev. V1 6 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz Rev. V1 7 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz Rev. V1 8 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz Rev. V1 9 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz DESIGN CONSIDERATIONS The MRF174 is a RF MOSFET power N-channel enhancement mode field-effect transistor (FET) designed for UHF power amplifier applications. M/A-COM RF MOSFETs feature a vertical structure with a planar design, thus avoiding the processing difficulties associated with V-groove power FETs. M/A-COM Application Note AN211A, FETs in Theory and Practice, is suggested reading for those not familiar with the construction and characteristics of FETs. The major advantages of RF power FETs include high gain, low noise, simple bias systems, relative immunity from thermal runaway, and the ability to withstand severely mismatched loads without suffering damage. Power output can be varied over a wide range with a low power dc control signal, thus facilitating manual gain control, ALC and modulation. DC BIAS The MRF174 is an enhancement mode FET and, therefore, does not conduct when drain voltage is applied. Drain current flows when a positive voltage is applied to the gate. See Figure 9 for a typical plot of drain current versus gate voltage. RF power FETs require forward bias for optimum performance. The value of quiescent drain current (IDQ) is not critical for many applications. The MRF174 was characterized at IDQ = 100 mA, which is the suggested minimum Rev. V1 value of IDQ. For special applications such as linear amplification, IDQ may have to be selected to optimize the critical parameters. The gate is a dc open circuit and draws no current. Therefore, the gate bias circuit may generally be just a simple resistive divider network. Some special applications may require a more elaborate bias system. GAIN CONTROL Power output of the MRF174 may be controlled from its rated value down to zero (negative gain) by varying the dc gate voltage. This feature facilitates the design of manual gain control, AGC/ALC and modulation systems. (see Figure 8.) AMPLIFIER DESIGN Impedance matching networks similar to those used with bipolar VHF transistors are suitable for MRF174. See M/ACOM Application Note AN721, Impedance Matching Networks Applied to RF Power Transistors. The higher input impedance of RF MOSFETs helps ease the task of broadband network design. Both small-signal scattering parameters and large-signal impedances are provided. While the s- parameters will not produce an exact design solution for high power operation, they do yield a good first approximation. This is an additional advantage of RF MOS power FETs. 10 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz Rev. V1 11 M/A-COM Technology Solutions Inc. (MACOM) and its affiliates reserve the right to make changes to the product(s) or information contained herein without notice. Visit www.macom.com for additional data sheets and product information. For further information and support please visit: https://www.macom.com/support MRF174 The RF MOSFET Line 125W, 200MHz Rev. V1 M/A-COM Technology Solutions Inc. All rights reserved. Information in this document is provided in connection with M/A-COM Technology Solutions Inc ("MACOM") products. These materials are provided by MACOM as a service to its customers and may be used for informational purposes only. Except as provided in MACOM's Terms and Conditions of Sale for such products or in any separate agreement related to this document, MACOM assumes no liability whatsoever. MACOM assumes no responsibility for errors or omissions in these materials. MACOM may make changes to specifications and product descriptions at any time, without notice. MACOM makes no commitment to update the information and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to its specifications and product descriptions. No license, express or implied, by estoppels or otherwise, to any intellectual property rights is granted by this document. THESE MATERIALS ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, RELATING TO SALE AND/OR USE OF MACOM PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, CONSEQUENTIAL OR INCIDENTAL DAMAGES, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. MACOM FURTHER DOES NOT WARRANT THE ACCURACY OR COMPLETENESS OF THE INFORMATION, TEXT, GRAPHICS OR OTHER ITEMS CONTAINED WITHIN THESE MATERIALS. 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