A pp li c a t i o n N o t e , R e v . 2 . 0 , O c t . 2 00 6 A p p li c a t i o n N o t e N o . 0 4 9 DECT Transmit - Receiver Switch Using Ultra Small PIN Diodes R F & P r o t e c ti o n D e v i c e s Edition 2006-10-11 Published by Infineon Technologies AG 81726 München, Germany © Infineon Technologies AG 2009. All Rights Reserved. LEGAL DISCLAIMER THE INFORMATION GIVEN IN THIS APPLICATION NOTE IS GIVEN AS A HINT FOR THE IMPLEMENTATION OF THE INFINEON TECHNOLOGIES COMPONENT ONLY AND SHALL NOT BE REGARDED AS ANY DESCRIPTION OR WARRANTY OF A CERTAIN FUNCTIONALITY, CONDITION OR QUALITY OF THE INFINEON TECHNOLOGIES COMPONENT. THE RECIPIENT OF THIS APPLICATION NOTE MUST VERIFY ANY FUNCTION DESCRIBED HEREIN IN THE REAL APPLICATION. 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Life support devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered. Application Note No. 049 DECT Transmit - Receiver Switch Using Ultra Small PIN Diodes Revision History: 2006-10-11, Rev. 2.0 Previous Version: 2000-07-28 Page Subjects (major changes since last revision) All Document layout change Application Note 3 Rev. 2.0, 2006-10-11 Application Note No. 049 DECT Transmit - Receive Switch Using Ultra Small PIN Diodes 1 DECT Transmit - Receive Switch Using Ultra Small PIN Diodes This application note covers a redesign of a PIN diode switch introduced in application note No. 007. It uses diodes in SCD80 and SOT343 package, 0603 size SMD components and a 0.25 mm high FR4 printed circuit board. Advantages • • • • Small real estate consumption on PCB Power consumption in transmit-mode only Low component count Low cost Schematic ANTENNA BAR63 -02W 50Ω λ/4 TX 47nH RX BAR81W 15pF 150pF +U I = +10mA for TX - Ant U = 0 ... -5V or open circuit for RX - Ant AN049_schematic.vsd Figure 1 Schematic Measured Data of Prototype Board Table 1 Measured data f = 1.89 GHz Transmit-state (I = +10 mA at +U-pin) Receive-state (U = -3 V at +U-pin) TX-Ant. Loss 0.47 dB RX-Ant. Loss 0.70 dB TX-RX Isolation 29.4 dB TX-RX Isolation 19.8 dB RX-Ant. Isolation 29.7 dB TX-Ant. Isolation 18.5 dB Due to the reduced width of a 50 Ω line on the thinner PCB material the losses are slightly higher than in application note No. 007. Please note that TX-RX Isolation is improved by 3 dB in transmit-mode and more than 6 dB in receive-mode. The applied -3 V at the +U control port for the small-signal measurement are not necessary in ‘real‘ operation. If +U is left open circuit in receive-mode, a small reverse bias is generated by the diodes, if there is still an RF signal from the transmitter. Application Note 4 Rev. 2.0, 2006-10-11 Application Note No. 049 DECT Transmit - Receive Switch Using Ultra Small PIN Diodes 1.1 Harmonic Distortion Measurements Measurement Setup TX-Port 1.9 GHz, +27 dBm power, harmonics more than 100 dB down RX-Port 50 Ω termination Ant.-Port Spectrum analyzer +U-Pin I = 5 mA and I = 10 mA Results Harmonics referred to TX-Port input level (+27 dBm): 3.8 GHz -87 dB @ I = 5 mA -92 dB @ I= 10 mA 5.7 GHz > -100 dB @ I = 5 mA > -100dB @ I = 10 mA Note: All ports must be DC-blocked during measurements Realization A N049_evaluation_board.vsd Figure 2 Evaluation Board Board size: 35 mm x 30 mm, Scale: 3:1 The demo board was made of 0.25 mm FR4 Epoxy material Application Note 5 Rev. 2.0, 2006-10-11 Application Note No. 049 DECT Transmit - Receive Switch Using Ultra Small PIN Diodes Component placement BAR63-02W BAR81W 47nH 15pF 150pF AN049_PCB_top_view.vsd Figure 3 Top view on assembled PCB Part list Table 2 Part list BAR81W PIN diode SOT343 Infineon BAR63-02W PIN diode SCD80 Infineon 15 pF Capacitor 0603 S+M 150 pF Capacitor 0603 S+M 47 nH Inductor 0603 S+M FR4, 0.25 mm Div. Printed circuit board Numeric computation This circuit was developed using Microwave Harmonica V 7.0. To compute the frequency response of the circuit the freely distributed S-Parameter files of the Infineon diodes were used. For the SMD inductor a simple parallel equivalent circuit was developed. Application Note 6 Rev. 2.0, 2006-10-11 Application Note No. 049 DECT Transmit - Receive Switch Using Ultra Small PIN Diodes Circuit file for simulation ****************************************************************** * INFINEON SMALL SIGNAL SEMICONDUCTORS * APPLICATION NOTE NO. 049 * DECT T/R-SWITCH WITH BAR81W/BAR63-02W ****************************************************************** * ANT * PORT 2 * O * | * |\ | | +---------------------+ * TX O--| >|--O--| LAMBDA/4 |------O-----O RX * PORT 1 |/ | +---------------------+ | PORT 3 * BAR63 +-----+ * -02W \ / * BAR81W \ / * ---+--* | * ---+--- GND * SUBSTRATE MATERIAL: * FR4, H=0.25MM, T=0.018MM, ER=4.4, TAND=0.024 ****************************************************************** * NOV. 1997 J.P. Schaffer ****************************************************************** AN049_sim ulation_file1.vsd Figure 4 Simulation file 1 LL: WAP: W50: WM: PM: 18.3MM 0.46MM 0.46MM 0.20MM 0.50MM ; Width of match ; Length of match BLK STEP 1 43 TRL 43 44 STEP 44 45 TRL 45 60 OST 60 CAP 60 0 TWO 60 70 OST 70 CAP 70 0 TRL 80 81 VIA 81 TRL 80 82 VIA 82 TRL 70 71 STEP 71 72 TRL 72 73 STEP 73 2 S_OFF: 2POR END W1=WAP W=WM W1=WM W=0.6MM W=0.6MM C=50fF 80 B81OF W=0.6MM C=50fF W=1MM D=0.5MM W=1MM D=0.5MM W=0.6MM W1=0.6MM W=WM W1=WM 1 2 W2=WM P=PM W2=0.6MM P=0.4MM P=0.4MM P=0.4MM P=1MM p=1MM P=0.8MM W2=WM P=PM W2=W50 SUB SUB SUB SUB SUB ; BAR81W OFF STA SUB SUB SUB SUB SUB SUB SUB SUB SUB AN049_sim ulation_file2.vsd Figure 5 Simulation file 2 Application Note 7 Rev. 2.0, 2006-10-11 Application Note No. 049 DECT Transmit - Receive Switch Using Ultra Small PIN Diodes BLK STEP TRL STEP TRL OST CAP TWO OST CAP TRL VIA TRL VIA TRL STEP TRL STEP S_ON: END BLK TRL TRL IND RES CAP OST ONE OST TRL TEE TRL TRL S_OFF TRL RXAN: END 1 43 43 44 44 45 45 60 60 60 0 60 70 80 70 70 0 80 81 81 80 82 82 70 71 71 72 72 73 73 2 2POR 1 2 W1=WAP W=WM W1=WM W=0.6MM W=0.6MM C=50fF B81ON W=0.6MM C=50fF W=1MM D=0.5MM W=1MM D=0.5MM W=0.6MM W1=0.6MM W=WM W1=WM W2=WM P=PM W2=0.6MM P=0.4MM P=0.4MM P=0.4MM P=1MM p=1MM P=0.8MM W2=WM P=PM W2=W50 SUB SUB SUB SUB SUB ; BAR81W ON STATE SUB SUB SUB SUB SUB SUB SUB SUB SUB ; SWITCH IN RECEIVE-MODE: TX-ANT OFF, RX-ANT ON 1 7 W=W50 P=4MM SUB 7 10 W=W50 P=3MM SUB 7 8 L=47nH ; Equivalent circuit of 8 0 R=2.0 ; 47nH S+M 0603 SMD inductor 7 0 C=140fF ; in parallel resonance 10 W=W50 P=0.6MM SUB 10 20 B63OF ; BAR63-02W OFF STATE 20 W=W50 P=0.6MM SUB 20 30 W=W50 P=0.54MM SUB 30 40 50 W1=W50 W2=WAP W3=W50 SUB 50 2 W=W50 P=10MM SUB 40 42 W=WAP P=LL SUB 42 75 ; Shunt Diode ON-State 75 3 W=W50 P=3MM SUB 3POR 1 2 3 ; 1=TX 2=ANT 3=RX AN049_sim ulation_file3.vsd Figure 6 Simulation file 3 Application Note 8 Rev. 2.0, 2006-10-11 Application Note No. 049 DECT Transmit - Receive Switch Using Ultra Small PIN Diodes BLK TRL TRL IND RES CAP OST ONE OST TRL TEE TRL TRL S_ON TRL TXAN: END ; SWITCH IN TRANSMIT-MODE: TX-ANT ON, RX-ANT OFF 1 7 W=W50 P=4MM SUB 7 10 W=W50 P=3MM SUB 7 8 L=47nH ; Equivalent circuit of 8 0 R=2.0 ; 47nH S+M 0603 SMD inductor 7 0 C=140fF ; in parallel resonance 10 W=W50 P=0.6MM SUB 10 20 B63ON ; BAR63-02W ON STATE 20 W=W50 P=0.6MM SUB 20 30 W=W50 P=0.54MM SUB 30 40 50 W1=W50 W2=WAP W3=W50 SUB 50 2 W=W50 P=10MM SUB 40 42 W=WAP P=LL SUB 42 75 ; Shunt Diode OFF-State 75 3 W=W50 P=3MM SUB 3POR 1 2 3 ; 1=TX 2=ANT 3=RX FREQ STEP END 100MHZ 3GHZ DATA SUB: MS H=0.25MM B81OF:DUMMY B81ON:DUMMY B63OF:DUMMY B63ON:DUMMY END 10MHZ ER=4.4 TAND=0.024 MET1=CU 18UM FILE=MU5V00U0.S2P FILE=MUV0010M.S2P FILE=PT5V00U0.S1P FILE=PTV0010M0.S1P AN049_sim ulation_file4.vsd Figure 7 Simulation file 4 Application Note 9 Rev. 2.0, 2006-10-11 Application Note No. 049 DECT Transmit - Receive Switch Using Ultra Small PIN Diodes Computation and measurement results Insertion Loss TX -> Antenna in Transmit-Mode 0 -2 -4 Insertion Loss [dB] -6 -8 Computation -10 Measurement -12 -14 -16 -18 -20 0 0,5 1 1,5 2 2,5 Frequency [GHz] 3 AN049_TX_Antenna.vsd Insertion Loss TX → Antenna in Transmit-Mode Figure 8 Insertion Loss Antenna -> RX in Transmit-Mode 0 -5 Insertion Loss [dB] -10 -15 Computation -20 Measurement -25 -30 -35 -40 0 0,5 1 1,5 2 Frequency [GHz] Figure 9 2,5 3 AN049_Antenna_RX.vsd Insertion Loss Antenna → RX in Transmit-Mode Application Note 10 Rev. 2.0, 2006-10-11 Application Note No. 049 DECT Transmit - Receive Switch Using Ultra Small PIN Diodes Insertion Loss TX -> RX in Transmit-Mode 0 -5 Insertion Loss [dB] -10 -15 Computation -20 Measurement -25 -30 -35 -40 0 0,5 1 1,5 2 2,5 3 Frequency [GHz] AN049_TX_RX.vsd Insertion Loss TX → RX in Tranmit-Mode Figure 10 Insertion Loss TX -> Antenna in Receive-Mode 0 -5 I nserti on Loss [dB] -10 -15 Computation -20 Measurement -25 -30 -35 -40 0 0,5 1 1,5 2 Freqency [GHz] Figure 11 2,5 3 AN049_TX_Antenna_receive.vsd Insertion Loss TX → Antenna in Receive-Mode Application Note 11 Rev. 2.0, 2006-10-11 Application Note No. 049 DECT Transmit - Receive Switch Using Ultra Small PIN Diodes Insertion Loss Antenna -> RX in Receive-Mode 0 -2 -4 Insertion Loss [dB] -6 -8 Computation -10 Measurement -12 -14 -16 -18 -20 0 0,5 1 1,5 2 2,5 Frequency [GHz] 3 AN049_Antenna_RX_receive.vsd Insertion Loss Antenna → RX in Receive-Mode Figure 12 Insertion Loss TX -> RX in Receive-Mode 0 -5 Insertion Loss [dB] -10 -15 Computation -20 Measurement -25 -30 -35 -40 0 0,5 1 1,5 2 Frequency [GHz] Figure 13 2,5 3 AN049_TX_RX_receive.vsd Insertion Loss TX → RX in Receive-Mode The computed isolation parameters are worse than measured. This is due to the dielectric losses of the material, which seem to be lower than assumed for simulation. Application Note 12 Rev. 2.0, 2006-10-11