UM9601_06

UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS DESCRIPTION Description The UM9601-UM9608 series of PIN diodes was developed for shunt mount applications in microstrip circuits. Good switch performance is demonstrated at frequencies from UHF to 4 GHz and higher. This performance is achieved using discrete low inductance Microsemi PIN diodes assembled with special hardware to permit good electrical and mechanical compatibility with microstrip transmission lines. Design information is presented for preparation of microstrip circuit boards to accommodate these PIN diodes. A detailed design for a 900 MHz quarter-wave antenna switch is given. This switch which employs a low cost UM9401 axial leaded PIN diode in conjunction with a UM9601 performs with 30 dB receiver isolation over a 100 MHz bandwidth and with a transmitter insertion loss of less than 0.4 dB. This switch can safely handle transmitter power levels up to 100 watts at infinite SWR. The Microsemi UM9601 series PIN diodes are constructed using a fused-in-glass which results in a highly reliable, hermetic package. The process utilizes symmetrical, full faced metallurgical bonds to both surfaces of the silicon chip. This construction greatly minimizes the normal parasitic inductance and capacitance found in conventional glass or ceramic packaged diodes which employ straps, springs, or whiskers. The use of discrete UM9601-UM9608 diodes greatly minimizes handling problems commonly associated with passivated PIN diode chips while maintaining good microwave performance. In addition the power handling capability of the UM9601-UM9608 series is considerably higher than PIN diode chips can provide. Environmentally, the UM9601-9608 series PIN diodes can withstand thermal cycling from -195 oC to +300 oC and exceed all military environmental specifications for shock, vibration, acceleration, and moisture. KEY FEATURES W WW . Microsemi . C OM Low Inductance Shunt Mount Package Characterized for Microstrip Microsemi Ruggedness and Reliability High Power Handling Capability Low Bias Current Requirement Excellent Distortion Properties Cost Effective in High Quantity Applications APPLICATIONS/BENEFITS RoHS compliant packaging available: use UMX9601, etc. IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com Typical Microwave Performance UM9601-9604 UM9605-UM9608 SPST SPST SPNT* SPST SPST SPNT* Insertion Loss Isolation Isolation Insertion Loss Isolation Isolation Frequency 0 Bias 100 mA 100 mA 0 Bias 100 mA 100 mA GHz dB dB dB dB dB dB 0.5 0.20 30 36 0.20 25 31 1.0 0.25 26 32 0.20 22 28 1.5 0.35 22 28 0.20 20 26 2.0 0.50 18 24 0.25 17 22 3.0 1.00 15 21 0.25 15 21 4.0 1.50 13 19 0.40 14 20 * Performance based on SPST Measurements in 0.025” (0.635mm) Microstrip Test Circuit. Note: All dimensions in inches and (millimeters). UM9601 SERIES UM9601 SERIES Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 1 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS Flange @ 25 oC Free Air Peak Power 1 µs Single Pulse at 25 oC Ambient Operating and Storage Temperature Maximum Ratings UM9601-UM9604 PD θ 7.5 W 20 oC/W 1.5 W 25 kW UM9605-UM9608 PD θ 4W 37.5 oC/W 0.5 W 10 kW W WW . Microsemi . C OM -65 oC to +175 oC Reverse Voltage Ratings @ 10 µA 400 V UM9602 UM9604 UM9606 UM9608 100 V UM9601 UM9603 UM9605 UM9607 Electrical Specifications (at 25 oC) Test Series Resistance Parallel Resistance Total Capacitance Carrier Lifetime Forward Voltage I-Region Width Symbol Rs Rp CT 100k 1.2 2.0 0.85 80 150 1.0 0.95 Min UM9601-UM9604 Typ Max 0.4 0.6 150k 0.5 Min UM9605-UM9608 Typ Max 1.5 1.7 Units Condition IF = 100 mA F = 100 MHz Vr = 100 V F = 100 MHz Vr = 100 V F = 1 MHz Ω Ω pF µs V µm ELECTRICALS ELECTRICALS τ VF W If = 10 mA IF = 100 mA Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 2 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS Selection Guide The following chart serves as a general guide for indicating the most likely diode from the series for a given application. Applications 1. High isolation switches to 2 GHz at low drive 2. Quarter-wave antenna switches to 100 watts 3. Priced for high volume commercial applications High voltage rating version of UM9601 and UM9603 Respectively for peak power handling to 3 kW 1. Low insertion loss switches to 4 GHz 2. Low distortion attenuator applications High voltage version of UM9605 and UM9607 For peak power handling to 10 kW Recommended Types UM9601 (Affixes to microstrip ground plane) UM9603 (Affixes to microstrip backing plate) UM9602 UM9604 UM9605 (Affixes to microstrip ground plane) UM9607 (Affixes to microstrip backing plate) UM9606 UM9608 W WW . Microsemi . C OM DIODE RESISTANCE vs DIODE CURRENT TYPICAL 105 F = 100 MHz 104 103 Rs (Ohms) UM9605 - UM9608 102 UM9601 - UM9604 10 1 10 0 ELECTRICALS ELECTRICALS 10 -1 10 -6 10 -5 -4 10 -3 10 -2 10 -1 10 10 0 If (mA) Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 3 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS PULSE THERMAL IMPEDANCE TYPICAL W WW . Microsemi . C OM PULSE THERMAL IMPEDANCE (C/W) 104 103 102 UM9605 - UM9608 101 UM9601 - UM9604 100 10-1 10-6 10-5 10-4 10-3 10-2 10-1 100 PULSE WIDTH (sec) Rp VERSUS VOLTAGE AND FREQUENCY UM9601 - UM9604 3 10 TYPICAL PARALLEL RESISTANCE (kOhms)) F=100 MHz 102 F=500 MHz F=1 GHz 101 ELECTRICALS ELECTRICALS F=3 GHz 100 100 101 102 103 REVERSE VOLTAGE (V) Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 4 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS W WW . Microsemi . C OM POWER RATING TYPICAL 12 PD MAX POWER DISSIPATION (W) 10 UM9601 - UM9604 8 6 4 2 UM9605 - UM9608 0 0 25 50 75 100 125 150 175 HEAT SINK TEMPERATURE (C) Rp vs VOLTAGE AND FREQUENCY UM9605-UM9608 103 TYPICAL 100 MHz PARALLEL RESISTANCE (kOhms) 10 2 500 MHz 1 GHz ELECTRICALS ELECTRICALS 3 GHz 101 10 0 10 0 10 1 2 10 10 3 REVERSE VOLTAGE (Vr) Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 5 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS W WW . Microsemi . C OM FORWARD BIAS INTERMODULATION DISTORTION VERSUS NOMINAL CARRIER FREQUENCY AT 20 dBm PER CHANNEL DISTORTION BELOW CARRIER (dB) 120 110 100 90 80 70 TYPICAL SECOND ORDER THIRD ORDER 60 50 40 100 If = 10 mA 101 102 F (MHz) THIRD ORDER INTERMODULATION DISTORTION VERSUS FORWARD BIAS CURRENT AT 20 dBm PER CHANNEL DISTORTION BELOW CARRIER (dB) 120 110 100 90 80 70 60 50 40 0 10 Fa = 43 MHz Fb = 44 MHz TYPICAL Fa = 7.4 MHz Fb = 7.6 MHz ELECTRICALS ELECTRICALS 10 1 10 2 If (mA) Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 6 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS W WW . Microsemi . C OM TYPICAL FORWARD BIAS THIRD ORDER INTERMODULATION DISTORTION vs INPUT POWER PER CHANNEL DISTORTION BELOW CARRIER (dBm) 110 R 2ab/a 100 Fa = 43 MHz 90 Fb = 44 MHz 80 Fa = 7.4 MHz 70 Fb = 7.6 MHz 60 50 40 30 20 0 10 20 30 40 INPUT POWER PER CHANNEL (dBm) REVERSE BIAS INTERMODULATION DISTORTION TYPICAL 110 DISTORTION BELOW CARRIER (dB) 100 90 80 70 THIRD ORDER SECOND ORDER ELECTRICALS ELECTRICALS 60 50 40 30 20 1 10 50 Fa = 43 MHz Fb = 44 MHz P = 20dBm PER CHANNEL REVERSE VOLTAGE (Vr) Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 7 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS W WW . Microsemi . C OM UM9601 UM9602 UM9603 UM9604 UM9605 UM9606 UM9607 UM9608 MECHANICAL MECHANICAL MECHANICAL Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 8 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS W WW . Microsemi . C OM Microwave Characterization The UM9601-UM9608 series has been designed and characterized as shunt switch elements at frequencies to 4 GHz in microstrip circuits. Performance curves are given which demonstrate switch performance in 0.025” (.635mm) alumina microstrip. The performance data were derived by evaluating externally biased microstrip circuits in which a UM9601 diode was installed. Each circuit consisted of a 1 inch length of 50 Ohm nominal impedance 0.025” (.635mm) thick alumina microstrip and two SMA connectors. The data shown include the board and connector loss. Measurements performed using 00.050” (1.27mm) alumina substrates show similar performance at frequencies to1.5 GHz These circuits simulate SPST switches. Many designs require multi-throw switches. It is important to recognize that a multi-throw switch will have 6dB higher isolation than indicated for SPST switches. Also, a multi-throw switch using shunt mounted PIN diodes require the diodes be placed a quarter-wavelength from the common port. A further improvement in switch performance may be achieved by using 2 shunt PIN diodes in each arm spaced a quarter-wavelength from each other. In this case the isolation of each section will be twice the dB value of the switch. The insertion loss due to the diodes should be less than twice the insertion loss of an SPST section due to the transforming effect of the quarter-wave line on the capacitance of a single diode. Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 9 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS ISOLATION vs FREQUENCY .025" (.635mm) ALUMINA MICROSTRIP SPST SWITCH DIODE CURRENT = 100 mA 1.6 TYPICAL W WW . Microsemi . C OM 1.4 1.2 UM9601 - UM9604 ISOLATION (dBm) 1.0 0.8 0.6 0.4 UM9605 - UM9608 0.2 0.0 0 1 2 3 4 5 6 FREQUENCY (GHz) ISOLATION vs FREQUENCY .025" (.635mm) ALUMINA MICROSTRIP SPST SWITCH DIODE CURRENT = 100 mA 30 TYPICAL 25 ISOLATION (dBm) UM9601 - UM9604 20 15 UM9605 - UM9608 10 5 0 0 1 2 3 4 FREQUENCY (GHz) Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 10 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS ISOLATION vs FREQUENCY AND DIODE CURRENT 0.025" (0.635mm) ALUMINA MICROSTRIP SPST SWITCH 28 26 1 GHz 24 UM9605 - UM9608 TYPICAL UM9601 - UM9604 W WW . Microsemi . C OM ISOLATION (dB) 22 20 18 16 14 12 10 8 6 10 100 1000 UM9601 - UM9604 3 GHz UM9605 - UM9608 DIODE CURRENT (mA) Installation in Microstrip The cup type flange on the UM9601, UM9602, UM9605, and UM9606 is designed to be affixed to the ground plane surface of a microstrip board. The UM9603, UM9604, UM9607, and UM9608 were designed to be affixed to a backing plate as shown. It was experimentally determined that at frequencies greater than 2 GHz the anode of the diode should be approximately 0.010” (.254mm) above the top surface of the microstrip for lowest insertion loss. Figure: UM9601/UM9602 Microstrip Mount This antenna switch uses a series mounted diode and a shunt mounted diode. The UM9601 was selected for shunt mounted device (SPST performance at 1 GHz: 0.2dB insertion loss and 25dB isolation) and because it is the lowest cost diode in the UM9601-UM9608 series. A UM9401 axial lead diode was chosen for the series mounted device. The performance of this switch is displayed in the graphs and in the following table. It should be noted that the loss values are actual measured numbers including losses due to the capacitors, bias networks, connectors, as well as the board. In a typical radio application where the antenna switch circuit board is integrated in the same microstrip board that contains transmitter and receiver elements the connector loss is eliminated. This will result in lower overall insertion loss values than indicated here. For solder adhesion the microstrip may be heated to solder melting temperature (up to 300 oC) with no damage to the diode. Conductive epoxy may also be employed. The thermal resistance of solder mounted UM9601-UM9604 in their test boards was less than 20 oC/W; for the UM9605-UM9608 thermal resistance was less than 30 oC/W. MECHANICAL MECHANICAL Design Example – 900 MHz Antenna Switch An example of a practical circuit design using a UM9601 diode is a quarter-wave antenna switch covering the frequency of 800-900 MHz. The circuit design for this switch is shown and was constructed using 0.025” (0.645mm) alumina microstrip. Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 11 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS where σ = maximum antenna SWR W WW . Microsemi . C OM Using resistance values for UM9401 and UM9601 the maximum transmitter power curve is given and shows that this circuit is able to handle 100 watts of transmitter power at 100 mA forward bias and totally mismatched antenna at an ambient temperature of 60 oC. For a perfectly match antenna the power handling increases to 400 watts under the same bias and ambient conditions. Distortion is an important consideration in the selection of a PIN diode antenna switch design. The UM9401 and UM9601 PIN diodes are designed for low distortion applications. The level of distortion produced by this 900 MHz antenna switch when operated in the transmit state (forward bias of 100 mA) is expected to be at least 90 dB below the carrier for a 50 watt transmitter level. In the receiver state (zero bias) the intermodulation distortion caused by two in-band signals at 0 dBm are estimated to be at least 100 dB below this level The CW power handling capacity is determined by the allowable power dissipation of the series mounted UM9401. Using a gap in the line of 0.190” (4.82mm) and lead soldered attached spacing of 0.250” (6.35mm) the power rating of the UM9401 is 6 watts at a 25 oC ambient. This was determined by performing a thermal resistance measurement on the circuit mount UM9401. The relationship that derives the maximum transmitter power, PT is: P  σ + 1 PT = DISS Zo  Rs  2σ  2 MAX. TRANSMITTER POWER vs FORWAD CURRENT FOR UM9601/UM9401 900 MHz MICROSTRIP ANTENNA SWITCH MAXIMUM TRANSMITTER POWER (W) 103 TYPICAL 102 Zo = 50 Ohms SWR = INFINITE 200mA 100 mA 101 50 mA 20 mA 10 mA 100 0 25 50 75 100 125 150 175 AMBIENT TEMPERATURE Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 12 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS W WW . Microsemi . C OM Antenna Switch Performance Frequency Range 800-900 MHz 1. Transmit State (I = 100 mA, TA = 60 oC) A. Maximum Transmitter Power 100 watts (antenna SWR = ∞) B. Maximum Transmitter Power 40 watts (antenna SWR = 1) C. Transmitter Insertion Loss 0.4 dB D. Receiver Isolation 31 dB E. Harmonic Distortion -90 dB (PT = 100 watts) II. Receive State (zero Bias) A. Receiver Isolation Loss 0.6-0.7 dB B. Intermodulation Distortion -100 dB PIN = 0 dBm Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 13 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS ANTENNA SWITCH INSERTION LOSS TYPICAL 1.0 W WW . Microsemi . C OM RECEIVER INSERTION INSERTION LOSS (dB) 0.8 LOSS (If=0) 0.6 If=20 mA If=50 mA 0.4 TRANSMITTER INSERTION LOSS (If=100 mA) 0.2 0.0 700 750 800 850 900 950 1000 FREQUENCY (MHz) RECEIVER ISOLATION vs FREQUENCY AND DIODE CURRENT TYPICAL 35 100 mA 50 mA 20 mA 30 10 mA ISOLATION (dB) 25 20 15 10 700 750 800 850 900 950 1000 FREQUENCY (MHz) Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 14 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS W WW . Microsemi . C OM Figure: Substrate Drawing Figure: Assembly Drawing Parts list F1 C1-C4 D1 D2 J1-J3 5000 pF Feed Through Filter 30 pF Chip Capacitor PIN Diode PIN Diode SMA Connector Substrate Erie 1270-016 Vitramon VJ0805A300KF Microsemi UM9401 Microsemi UM9601 Cableware 971-028 Vectronics Microwave 79-9081-0401 Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 15 UM9601 – UM9608 FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES C OS O S AND MICROWAVE APPLICATIONS NOTES: W WW . Microsemi . C OM Copyright  2005 Rev. 0, 2006-01-17 Microsemi Page 16