HMC121C8 MICROWAVE CORPORATION GaAs MMIC SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz FEBRUARY 2001 V03.0400 Features General Description WIDE BANDWIDTH: DC - 10 GHz The HMC121C8 is an absorptive Voltage Variable Attenuator (VVA) in a non-hermetic surface-mount package covering DC - 10 GHz. It features an on-chip reference attenuator for use with an external op-amp to provide simple single voltage attenuation control, 0 to -3V. The device is ideal in designs where an analog DC control signal must control RF signal levels over a 25 dB amplitude range. Applications include AGC circuits and temperature compensation of multiple gain stages in microwave point-topoint and VSAT radios. See HMC121G8 for a hermetic SMT version of this device. LOW PHASE SHIFT VS. ATTENUATION SMT ATTENUATORS 2 25 dB ATTENUATION RANGE SIMPLIFIED VOLTAGE CONTROL Guaranteed Performance, 50 ohm system, -55 to +85 deg C Parameter Min Typical Max Units 2.0 2.2 3.5 2.5 3.2 4.5 dB dB dB Inse rtion L oss DC - 6 GHz : DC - 8 GHz : DC - 10 GHz : Attenuation Range DC - 6 GHz: DC - 10 GHz : 20 25 25 30 dB Return Loss DC - 8 GHz: DC - 10 GHz : 11 8 15 12 dB dB 3 6 ns ns +3 -3 dBm dBm +18 +10 dBm dBm Switching Characteristics tRISE, tFALL (10/90% RF): tON, tOFF (50% CTL to 10/90% RF): Input Power for 0.25 dB C ompre ssion (0.5 - 10 GHz) Min. Atten: Atten. >2 dB: Input Third Order Intercept (two - 8 dBm signals, 0.5 - 10 GHz) Min. Atten: 12 Elizabeth Drive, Chelmsford, MA 01824 2 - 14 Phone: 978-250-3343 Fax: 978-250-3373 Web Site: www.hittite.com HMC121C8 MICROWAVE CORPORATION HMC121C8 SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz FEBRUARY 2001 V03.0400 Insertion Loss Relative Attenuation 0 0 -2 -3 +85 C -4 -10 6 dB 2 -30 2 4 6 8 10 12 0 2 4 FREQUENCY (GHz) 12 dB 6 8 10 12 25 30 25 30 FREQUENCY (GHz) Relative Attenuation vs. Control Voltage @ 4.2 GHz Return Loss 0 0 V2 CONTROL VOLTAGE (Vdc) -5 S11 RETURN LOSS (dB) 18 dB -40 0 -10 -15 -20 -25 S22 -0.5 -1 -1.5 -2 -30 -2.5 -35 -3 V1 0 2 4 6 8 10 12 0 5 FREQUENCY (GHz) 10 15 Relative Attenuation vs. Control Voltage @ 10 GHz 85 0 24 dB 75 V2 CONTROL VOLTAGE (Vdc) 21 dB 65 15 dB 55 20 RELATIVE ATTENUATION (dB) Relative Phase RELATIVE PHASE (DEG) 0 dB -20 24 dB -5 3 dB 9 dB 45 35 3 dB 25 15 5 -5 -0.5 -1 -1.5 -2 -2.5 V1 -3 0 2 4 6 8 10 12 FREQUENCY (GHz) 12 Elizabeth Drive, Chelmsford, MA 01824 0 5 10 15 20 RELATIVE ATTENUATION (dB) Phone: 978-250-3343 Fax: 978-250-3373 Web Site: www.hittite.com 2 - 15 SMT ATTENUATORS +25 C ATTENUATION (dB) INSERTION LOSS (dB) -40 C -1 HMC121C8 MICROWAVE CORPORATION HMC121C8 SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz V03.0400 FEBRUARY 2001 Input Second Order Intercept vs. Attenuation SECOND ORDER INTERCEPT (dBm) 30 Reference 25 10 dB 20 15 6 dB 10 3 dB 5 0 1 2 3 4 5 6 7 8 9 60 Reference 3 dB 50 40 30 10 dB 6 dB 20 10 10 0 1 2 3 FREQUENCY (GHz) 4 5 6 7 8 9 10 8 9 10 FREQUENCY (GHz) 0.25 dB Compression vs. Attenuation 1 dB Compression vs. Attenuation 15 15 Reference 1 dB COMPRESSION (dBm) 0.25 dB COMPRESSION (dBm) 10 Reference 5 6 dB 0 -5 10 5 0 6 dB -5 -10 -10 0 1 2 3 4 5 6 7 8 9 10 0 1 2 FREQUENCY (GHz) 3 4 5 6 7 FREQUENCY (GHz) Second Harmonic vs. Attenuation 70 SECOND HARMONIC (dBc) SMT ATTENUATORS 2 THIRD ORDER INTERCEPT (dBm) Input Third Order Intercept vs. Attenuation 3 dB Reference 60 50 6 dB 40 10 dB 30 0 1 2 3 4 5 6 7 8 9 10 FREQUENCY (GHz) 12 Elizabeth Drive, Chelmsford, MA 01824 2 - 16 Phone: 978-250-3343 Fax: 978-250-3373 Web Site: www.hittite.com HMC121C8 MICROWAVE CORPORATION HMC121C8 SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz V03.0400 FEBRUARY 2001 Schematic Absolute Maximum Ratings 50 50 RF1 RF Input +16dBm Control Voltage Range +1.0 to -6.0 Vdc Storage Temperature -65 to +150 deg C Operating Temperature -55 to +85 deg C RF2 500 500 500 V2 I O V1 Outline Drawing 1. 2. 3. 4. 5. 12 Elizabeth Drive, Chelmsford, MA 01824 2 SMT ATTENUATORS 500 Phone: 978-250-3343 MATERIAL: A) PACKAGE BODY & COVER : WHITE ALUMINA (92%) B) LEADS & PACKAGE BOTTOM: COPPER PLATING : ELECTROLYTIC GOLD 100 - 200 MICROINCHES OVER ELECTROLYTIC NICKEL 100 TO 200 MICROINCHES. DIMENSIONS ARE IN INCHES (MILLIMETERS). UNLESS OTHERWISE SPECIFIED TOL. ARE ±0.005(±0.13). ALL UNLABELED LEADS ARE GROUND. THESE LEADS ARE CONNECTED INTERNALLY TO THE PACKAGED BOTTOM GROUND. THE PACKAGE BOTTOM RF GROUND MUST BE SOLDERED TO THE PCB RF GROUND. PACKAGE LENGTH AND WIDTH DIMENSIONS SHOWN DO NOT INCLUDE LID SEAL PROTRUSION. ALLOWABLE PROTRUSION SHALL BE 0.005 (0.127MM) PER SIDE. Fax: 978-250-3373 Web Site: www.hittite.com 2 - 17 HMC121C8 MICROWAVE CORPORATION HMC121C8 SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz FEBRUARY 2001 V02.0400 Single-Line Control Driver 50 50 RF1 RF2 2 SMT ATTENUATORS 500 500 500 500 V2 I O V1 CTL +5V 500 1N4148 3.9K 500 3.9K TL321 OR EQUIVALENT -5V External op-amp control circuit maintains impedance match while attenuation is varied. Input control ranges from 0 Volts (min. attenuation) to -2.5 Volts (max. attenuation.) 12 Elizabeth Drive, Chelmsford, MA 01824 2 - 18 Phone: 978-250-3343 Fax: 978-250-3373 Web Site: www.hittite.com HMC121C8 MICROWAVE CORPORATION HMC121C8 SMT VOLTAGE-VARIABLE ATTENUATOR DC - 10 GHz FEBRUARY 2001 V02.0400 Evaluation PCB SMT ATTENUATORS 2 The circuit board used in the final application should be generated with proper RF circuit design techniques. Signal lines at the RF port should have 50 ohm impedance and the package ground leads and package bottom ground should be connected directly to the ground plane similar to that shown above. The evaluation circuit board shown above is available from Hittite Microwave Corporation upon request. List of Material Item Description J1 - J2 PC Mount SMA RF Connector J3 - J7 DC PIN U1 HMC121C8 VVA PCB * 102084 Eval Board * Circuit Board Material : Rogers 4350 12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Web Site: www.hittite.com 2 - 19