AN3021 PIN Diodes for Microwave Switch Designs Rev. V2 Introduction This Application Note is intended to provide practical guidance in the selection of PIN Diodes for switch control circuit functions. Switches, Digital and Analog Attenuators, and Limiters each have unique functions that require proper device selection. The design difficulty lies within the parametric translation from Diode Specifications, to the circuit designers’ Microwave Specifications. Diode parametric language such as Vb, Vf, Ct, Rs, τL, θ, must convert into Insertion Loss, VSWR, Isolation, P1dB, Input IP3, RF Operating Power, RF Power Dissipation, and D.C. Power Consumption Specification Terminology. In addition to actual diode parameters, package parasitics play a significant role in determining switch circuit performance. Package capacitance, package inductance, package electrical resistance, and package thermal impedance are extremely important considerations to determine the effective frequency bandwidth and maximum incident power for reliable switch operation. The manufacturing methodology dictates the type of diode selection. Surface mount assembly will mandate the usage of either plastic, HMIC SURMOUNT, or MELF & HiPAX ceramic devices. Chip and Wire ( Hybrid ) manufacturing will determine the usage of Cermachips, Flip Chips, or Beam Lead Devices. Schematics for the most common switch designs: Series-Exclusive, Shunt-Exclusive, and Series-Shunt are outlined below for consideration. The Decision Making Process for PIN Diode Selection for Microwave Switch Design The following procedure outlines and Effective Process for PIN Diode Selection for Switch Design. 1. Determine the Preferred Type of Manufacturing for the PIN Diode in the Switch Design: Surface Mount or Chip and Wire (Hybrid) Manufacturing. 2. Determine the Frequency of Operation and RF Power Handling of the Switch Design. 3. Use Table 1, “Relative Switch Performance and Design Evaluation Matrix” to determine the Type of Switch Design that Best Satisfies the Particular Switch Specifications and Requirements. 4. Use Table 2, “Relative PIN Diode Performance Evaluation Matrix” to Determine the Type of PIN Diode that Best Satisfies the Switch Design Selected from Table 1. 5. Use Table 3, “PIN Diode P/N Series Matrix” to Determine the PIN Diode P/N Series that Best Satisfies the Type of PIN Diode Selected from Table 2. 1 ADVANCED: Data Sheets contain information regarding a product M/A-COM Technology Solutions • North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400 is considering for development. Performance is based on target specifications, simulated results, • India Tel: +91.80.43537383 • China Tel: +86.21.2407.1588 and/or prototype measurements. Commitment to develop is not guaranteed. Visit www.macomtech.com for additional data sheets and product information. PRELIMINARY: Data Sheets contain information regarding a product M/A-COM Technology Solutions has under development. Performance is based on engineering tests. Specifications are typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available. M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make Commitment to produce in volume is not guaranteed. changes to the product(s) or information contained herein without notice. AN3021 PIN Diodes for Microwave Switch Designs Rev. V2 Table 1: Relative Switch Performance and Design Evaluation Matrix Switch Design Configuration Parameter Series Diodes Exclusive Shunt Diodes Exclusive Series-Shunt Diodes Insertion Loss Worst Moderate Best VSWR Moderate Worst Best Isolation Worst Moderate Best P1dB Moderate Moderate Moderate Input IP3 Moderate Moderate Moderate RF Incident Power Worst Best Moderate RF Power Dissipation Worst Best Moderate Switching Speed Worst Best Moderate D.C. Power Consumption Best (Single +5 V) Moderate (+5 V, -5 V) Worst (+5 V, -5 V) PIN Diode Driver Design Simplicity Best (+5 V Only) Moderate (+5 V, -5 V) Moderate (+5 V, -5 V) RF Design Simplicity Best Worst Moderate Cost Best Moderate Moderate Overall Evaluation 34 Points 38 Points 40 Points Notes: Evaluation based upon following grading : Best = 5 Points, Moderate = 3 Points, Worst = 1 Point. The higher the score, the better the overall relative design advantage. Where there is No significant relative advantage, a “ Moderate ” weighting can be used. Assumptions for SP2T Design: Design is a Reflective SP2T. (2) Diodes are used per RF port. Frequency Bandwidth is 3.0 : 1 maximum. Conclusions: The Series-Shunt Design is the Best in terms of Overall Switch Performance and value. Since each Design has a specific advantage, the decision for a Switch Design Selection is determined by the Specific Design Priorities for the requirement. 2 ADVANCED: Data Sheets contain information regarding a product M/A-COM Technology Solutions • North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400 is considering for development. Performance is based on target specifications, simulated results, • India Tel: +91.80.43537383 • China Tel: +86.21.2407.1588 and/or prototype measurements. Commitment to develop is not guaranteed. Visit www.macomtech.com for additional data sheets and product information. PRELIMINARY: Data Sheets contain information regarding a product M/A-COM Technology Solutions has under development. Performance is based on engineering tests. Specifications are typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available. M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make Commitment to produce in volume is not guaranteed. changes to the product(s) or information contained herein without notice. AN3021 PIN Diodes for Microwave Switch Designs Rev. V2 Table 2: Relative PIN Diode Performance Evaluation Matrix Surface Mount Assembly Key Parameter Plastic 1 MHz < F < 1 GHz 100 MHz < F < 4 GHz MELF or HiPax Chip & Wire Hybrid Assembly SURMOUNT Cerma Chip Flip Chip Beam Lead Best Selection Best Selection Best Selection Best Selection 4 GHz < F < 20 GHz Best Selection 20 GHz < F < 60 GHz 100 MHz < F < 20 GHz Best Selection Pinc < 0.1 W 0.1 W < Pinc < 1 W Best Selection Best Selection Best Selection 1 W < Pinc < 20 W Best Selection 20 W < Pinc < 200 W Relative Cost Index Best Selection Lowest Best Selection Moderate/Highest Moderate/Highest Lowest Moderate Highest Conclusions: 1. Plastic Devices are best suited where Cost is a decision driver, the Operating Frequency < 4 GHz, and the RF C.W. Incident Power < 1 W ( + 30 dBm ). 2. MELF or HIPAX Ceramic Devices are best utilized where Highest Average Power ( > 20 W C.W. ) is the Primary Design Goal and the Operating Frequency < 1 GHz. 3. SURMOUNT Devices are probably the Best Overall Compromise in Device Selection. They can Operate ( In Various bands ) from 10 MHz – 20 GHz and Perform well with RF Incident Power < 20 W C.W ( + 43 dBm ). 4. Cermachip Devices provide the Best Overall Performance for Operating Frequeny ( 100 MHz – 20 GHz ) , and RF Incident Power < 200 W C.W (+ 53 dBm ). 5. Flip Chip Devices are best suited for mmwave Frequencies < 60 GHz, where the RF Incident C.W. < 1W ( + 30 dBm ) and Conductive Epoxy or Soldering is Required. 6. Beam Lead Devices are best suited for mmwave Frequencies < 60 GHz, where the RF Incident C.W. < 0.1W ( + 20 dBm ) and Thermo Compression Bonding is Required. 3 ADVANCED: Data Sheets contain information regarding a product M/A-COM Technology Solutions • North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400 is considering for development. Performance is based on target specifications, simulated results, • India Tel: +91.80.43537383 • China Tel: +86.21.2407.1588 and/or prototype measurements. Commitment to develop is not guaranteed. Visit www.macomtech.com for additional data sheets and product information. PRELIMINARY: Data Sheets contain information regarding a product M/A-COM Technology Solutions has under development. Performance is based on engineering tests. Specifications are typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available. M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make Commitment to produce in volume is not guaranteed. changes to the product(s) or information contained herein without notice. AN3021 PIN Diodes for Microwave Switch Designs Rev. V2 Table 3: PIN Diode Part Number Series Matrix Plastic PIN Diodes MELF & HiPax PIN Diodes SURMOUNT PIN Diodes Cermachip PIN Diodes Flip Chip PIN Diodes Beam Lead PIN Diodes Part Numbers: Part Numbers: Part Numbers: Part Numbers: Part Numbers: Part Numbers: MA4P275 Series MA4P282 Series MA4P789 Series MA4P274 Series MA4P1250 MA4P1450 MA4P4000 Series MA4P4300 Series MA4P7000 Series MA4P7100 Series MA4PH23X Series MA4SPS Series MADP-042XXX Series MA4P102 MA4P202, 203 MA4P303 MA4P404 MA4P504 MA4P505 MA4P604 MA4P606 MA4PK2000, 3000 MA4FPC Series MA4AGFCP Series MA4AGSBP Series MA4PBL Series MA4AGBLP Series Notes: The following M/A-COM PIN Diode Drivers Operating with +5 V & -5 V D.C. Power Supplies are Practical with Many PIN Diode Switch Designs: DR65 Series, MADRMA0001 and MADRMA0002 Series. M/A-COM Website Homepage Hyperlink Address: http://www.macom.com 4 ADVANCED: Data Sheets contain information regarding a product M/A-COM Technology Solutions • North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400 is considering for development. Performance is based on target specifications, simulated results, • India Tel: +91.80.43537383 • China Tel: +86.21.2407.1588 and/or prototype measurements. Commitment to develop is not guaranteed. Visit www.macomtech.com for additional data sheets and product information. PRELIMINARY: Data Sheets contain information regarding a product M/A-COM Technology Solutions has under development. Performance is based on engineering tests. Specifications are typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available. M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make Commitment to produce in volume is not guaranteed. changes to the product(s) or information contained herein without notice. AN3021 PIN Diodes for Microwave Switch Designs Rev. V2 Schematic 1: SP2T Series Exclusive PIN Diode Switch, 40 dB Isolation with +5 V Supply +5V 1K SN5406 Open Collector + 5V TTL Driver J1 +5V 270 Ω B2 Bias J2 J3 B3 Bias +5V RF Series Diodes 1K SN5406 Open Collector + 5V TTL Driver Forward Bias Diode Voltage, ΔVf @ 10 mA ~ + 0.9 V Reverse Bias Diode Voltage = - ( +5 V - +2.3 V ) = - 2.7 V Schematic 1: D.C. Bias to RF Truth Table RF State B2 Bias B3 Bias Low Loss J1-J2 & Isolation J1-J3 +0.5 V @ 10 mA +5 V @ 0 mA Low Loss J1-J3 & Isolation J1-J2 +5 V @ 0 mA +0.5 V @ 10 mA 5 ADVANCED: Data Sheets contain information regarding a product M/A-COM Technology Solutions • North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400 is considering for development. Performance is based on target specifications, simulated results, • India Tel: +91.80.43537383 • China Tel: +86.21.2407.1588 and/or prototype measurements. Commitment to develop is not guaranteed. Visit www.macomtech.com for additional data sheets and product information. PRELIMINARY: Data Sheets contain information regarding a product M/A-COM Technology Solutions has under development. Performance is based on engineering tests. Specifications are typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available. M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make Commitment to produce in volume is not guaranteed. changes to the product(s) or information contained herein without notice. AN3021 PIN Diodes for Microwave Switch Designs Rev. V2 Schematic 2: SP2T All Shunt, 60 dB Isolation Design with 90° Transformer using Distributed Transmission Line J1 B2 B3 J3 θ = 90° θ = 90° θ = 90° θ = 90° θ = 90° θ = 90° J2 θ = 90 ° = β * L = ( 2 π / λ ) * L, L = λ/4 = [ 11.807 / ( εeff ½ * Fo * 4 ) ] inches. Fo = ( Fmin * Fmax )½ is in GHz, εeff is Effective Dielectric Constant of Transmission Line Medium and Air. Schematic 2: D.C. Bias to RF Truth Table RF State B2 Bias B3 Bias Low Loss J1-J2 & Isolation J1-J3 -V @ 0 mA +1 V @ (+20 mA per Diode) Low Loss J1-J3 & Isolation J1-J2 +1 V @ (+20 mA per Diode) -V @ 0 mA 6 ADVANCED: Data Sheets contain information regarding a product M/A-COM Technology Solutions • North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400 is considering for development. Performance is based on target specifications, simulated results, • India Tel: +91.80.43537383 • China Tel: +86.21.2407.1588 and/or prototype measurements. Commitment to develop is not guaranteed. Visit www.macomtech.com for additional data sheets and product information. PRELIMINARY: Data Sheets contain information regarding a product M/A-COM Technology Solutions has under development. Performance is based on engineering tests. Specifications are typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available. M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make Commitment to produce in volume is not guaranteed. changes to the product(s) or information contained herein without notice. AN3021 PIN Diodes for Microwave Switch Designs Rev. V2 Schematic 3: SP2T All Shunt, 30 dB Isolation Design using π, C-L-C Lumped Element 90° Transformer J1 B3 B2 J3 J2 θ = 90 Deg θ = 90 Deg C L C C L C L = Zo / (2π * Fo) C = 1 / (2π *Fo * Zo) 1/2 Fo = (Fmin* Fmax) Schematic 3: D.C. Bias to RF Truth Table RF State B2 Bias B3 Bias Low Loss J1-J2 & Isolation J1-J3 -V @ 0 mA +1 V @ +20 mA Low Loss J1-J3 & Isolation J1-J2 +1 V @ +20 mA -V @ 0 mA 7 ADVANCED: Data Sheets contain information regarding a product M/A-COM Technology Solutions • North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400 is considering for development. Performance is based on target specifications, simulated results, • India Tel: +91.80.43537383 • China Tel: +86.21.2407.1588 and/or prototype measurements. Commitment to develop is not guaranteed. Visit www.macomtech.com for additional data sheets and product information. PRELIMINARY: Data Sheets contain information regarding a product M/A-COM Technology Solutions has under development. Performance is based on engineering tests. Specifications are typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available. M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make Commitment to produce in volume is not guaranteed. changes to the product(s) or information contained herein without notice. AN3021 PIN Diodes for Microwave Switch Designs Rev. V2 Schematic 4: SP2T Series-Shunt, 40 dB Isolation Design with Positive & Negative Bias Current J1 B3 B2 330 Ω J2 J3 Series Diode Series Diode Shunt Diode Shunt Diode Schematic 4: D.C. Bias to RF Truth Table RF State B2 Bias B3 Bias Low Loss J1-J2 & Isolation J1-J3 -4 V @ 10 mA +1 V @ +10 mA Low Loss J1-J3 & Isolation J1-J2 +1 V @ +10 mA -4 V @ -10 mA 8 ADVANCED: Data Sheets contain information regarding a product M/A-COM Technology Solutions • North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400 is considering for development. Performance is based on target specifications, simulated results, • India Tel: +91.80.43537383 • China Tel: +86.21.2407.1588 and/or prototype measurements. Commitment to develop is not guaranteed. Visit www.macomtech.com for additional data sheets and product information. PRELIMINARY: Data Sheets contain information regarding a product M/A-COM Technology Solutions has under development. Performance is based on engineering tests. Specifications are typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available. M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make Commitment to produce in volume is not guaranteed. changes to the product(s) or information contained herein without notice. AN3021 PIN Diodes for Microwave Switch Designs Rev. V2 Schematic 5: SP2T Series-Shunt, 40 dB Isolation Design with +5 V Supply +5V +5V J1 330 Ω 330 Ω +5V +5V +5V 330 Ω B2 Series Bias B3 Series Bias SN7406 Open Collector + 5V TTL Driver SN7406 Open Collector + 5V TTL Driver B0 Voltage J3 B3 Shunt Bias +5V J2 B2 Shunt Bias +5V +5V +5V 330 Ω 330 Ω SN7406 Open Collector + 5V TTL Driver SN7406 Open Collector + 5V TTL Driver Schematic 5: D.C. Bias to RF Truth Table RF State B2 Series Bias B2 Shunt Bias B3 Series Bias B3 Shunt Bias B0 Voltage J1-J2 Low Loss & J1-J3 Isolation +0.5 V @ 11 mA +5 V @ 0 mA +1.4 V @ +11 mA (To J3 Shunt Diode) +0.5 V @ +11 mA +1.4 V J1-J3 Low Loss & J1-J2 Isolation +1.4 V @ +11 mA (To J2 Shunt Diode) +0.5 V @ +11 mA +0.5 V @ +10 mA +5 V @ 0 mA +1.4 V Notes: 1. Forward Bias Diode ∆Vf @ 10 mA ~ +0.9 V 2. Reverse Bias Series Diode = (+1.4 V - +1.4 V) = 0 V 3. Reverse Bias Shunt Diode = (+0.5 V - +5.0 V) = -4.5 V 9 ADVANCED: Data Sheets contain information regarding a product M/A-COM Technology Solutions • North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400 is considering for development. Performance is based on target specifications, simulated results, • India Tel: +91.80.43537383 • China Tel: +86.21.2407.1588 and/or prototype measurements. Commitment to develop is not guaranteed. Visit www.macomtech.com for additional data sheets and product information. PRELIMINARY: Data Sheets contain information regarding a product M/A-COM Technology Solutions has under development. Performance is based on engineering tests. Specifications are typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available. M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make Commitment to produce in volume is not guaranteed. changes to the product(s) or information contained herein without notice. AN3021 PIN Diodes for Microwave Switch Designs Rev. V2 Schematic 6: TR Switch Schematic with 25 dB Isolation Design with +3 V Supply Ant θ = 90 ° @ Fo L Tx Rx C C B1 Bias Schematic 6: TR Switch D.C. Bias to RF Truth Table RF State B1 Bias Low Loss Tx - Ant & Isolation Rx - Tx +2 V @ +10 mA Low Loss Ant - Rx & Isolation Tx - Rx 0 V @ 0 mA For Lumped Electrical Transmission Line Length, θ, between Junction and Rx Shunt Diode : L = Zo/ (2π Fo) , C = 1/ (2π Fo Zo) , Where Fo is the Resonant Frequency = ( F1 * F2 ) ½ & F1 & F2 are Band Edge Frequencies. 10 ADVANCED: Data Sheets contain information regarding a product M/A-COM Technology Solutions • North America Tel: 800.366.2266 • Europe Tel: +353.21.244.6400 is considering for development. Performance is based on target specifications, simulated results, • India Tel: +91.80.43537383 • China Tel: +86.21.2407.1588 and/or prototype measurements. Commitment to develop is not guaranteed. Visit www.macomtech.com for additional data sheets and product information. PRELIMINARY: Data Sheets contain information regarding a product M/A-COM Technology Solutions has under development. Performance is based on engineering tests. Specifications are typical. Mechanical outline has been fixed. Engineering samples and/or test data may be available. M/A-COM Technology Solutions Inc. and its affiliates reserve the right to make Commitment to produce in volume is not guaranteed. changes to the product(s) or information contained herein without notice.