PilJae Park 2/23/2007 Slide 1 Transmit/Receive (T/R) Switch Topology Comparison Series-series Topology Series-shunt Topology High impedance block  In Tx mode High power handling capability is required Leakage to Rx path is bottleneck of power handling  High impedance block in the Rx path is required in series-shunt topology

PilJae Park 2/23/2007 Slide 2 Proposed T/R Switch  Series topology for Tx path, series/shunt LC tank for Rx path For Tx mode, V C is high and L 1, C 1 forms parallel LC resonance tank For Rx mode, V C is low and L 1, C 2 forms series LC resonance tank  Tx path has small area and high Power handling capability  Low IL input matching network can be absorbed into T/R switch In Triple Well

PilJae Park 2/23/2007 Slide 3 Triple well MOS switch Inductive body bias MOS switch [2] Proposed Floating Triple Well Tx Switch Advantages Twin well MOS switch  Floating Triple well provides isolation to substrate Prevent power loss through the substrate Smaller area, wider bandwidth compared to the LC-tuned body bias technique

PilJae Park 2/23/2007 Slide 4 Floating Triple well MOS Tx Switch Body Impedance  Floating wells has better substrate isolation than LC tank Effective substrate impedance of high-Q LC tank is still less than 2 k  Smaller area and wider bandwidth

PilJae Park 2/23/2007 Slide 5 Low IL Matching between T/R Switch and LNA  Rx path of switch incorporates the LNA input matching network to achieve lower IL and noise figure Rx path IL of conventional T/R switch = IL of switch + IL of matching network

PilJae Park 2/23/2007 Slide 6 T/R Switch Design  Tx switch design for low IL and high isolation  Rx path design consideration with inductor Q  Simulation results of Tx and Rx path Tx path of T/R siwth Rx path of T/R siwth

PilJae Park 2/23/2007 Slide 7 Tx Switch Equivalent Circuit Model  Triple well NMOS equivalent circuit model Triple well NMOS cross-section view

PilJae Park 2/23/2007 Slide 8 Insertion loss of Tx Switch  IL of on Tx switch is a function of R on and Z j IL [dB] 1.0 dB 1.5 dB 2.0 dB 0.5 dB

PilJae Park 2/23/2007 Slide 9 Isolation Plot of Tx Switch 15 dB 20 dB 25 dB 30 dB 35 dB  Isolation of off Tx switch is a function of C’ sd and Z j

PilJae Park 2/23/2007 Slide 10 Tx Switch Transistor Sizing Tradeoff  Tradeoff between IL and isolation width ↑, IL ↓ and width ↓, isolation ↑  Green dotted line indicates transistor width meeting isolation  Blue line points out transistor width satisfying IL specification IL < 1 dB Isolation > 15 dB

PilJae Park 2/23/2007 Slide 11 Insertion Loss of Rx Path in the T/R Switch L1 : 5nH, C1 : 950fF M1: 100u/120n  High Q inductor is desirable for lower receive IL IL is about 0.5 dB when Q is 10

PilJae Park 2/23/2007 Slide 12 Isolation of between Tx Signal to Tx Path in the T/R Switch L1 : 5nH, C1 : 950fF M1: 100u/120n  High Q inductor is desirable for high isolation Isolation is about 17 dB when Q is equal to 10

PilJae Park 2/23/2007 Slide 13 Tx Path P1dB Simulation Results of T/R Switch  All switches are on in Tx mode  P in at Tx port P out at Ant port for Tx mode P 1dB simulation  31 dBm of P 1dB is achieved

PilJae Park 2/23/2007 Slide 14 Rx Matching Simulation Results of T/R Switch  Matching between Ant and Rx is >20 dB at 2.3 GHz

PilJae Park 2/23/2007 Slide 15 Insertion Loss of T/R switch  Tx IL = 0.9 dB at 2.3 GHz  Rx IL = 1.3 dB at 2.3 GHz

PilJae Park 2/23/2007 Slide 16 Isolation Simulation Results  Tx port to Rx port isolation >23 dB at 2.3 GHz

PilJae Park 2/23/2007 Slide 17 T/R Switch Layout  8-metal, 1-poly UMC 130-nm technology  Area of 500 μm x 500 μm including test pads core 230 μm x180 μm 500 μm

PilJae Park 2/23/2007 Slide 18 Performance Summary  Our design achieves the highest P 1dB with comparable IL and isolation

PilJae Park 2/23/2007 Slide 19 References [1] “A 5GHz 108Mb/s 2x2 MIMO Transceiver with Fully Integrated +16dBm PAs in 90nm CMOS”, Palaskas, Y et al, Solid-State Circuits, 2006 IEEE International Conference, Feb. 6-9, 2006 Page(s): [2] “Integrated CMOS transmit-receive switch using LC-tuned substrate bias for 2.4-GHz and 5.2-GHz applications”, Talwalkar, N.A. et al, EEE Journal of Solid-state circuit, Volume 39, Issue 6, June [3] “21.5-dBm power-handling 5-GHz transmit/receive CMOS switch realized by voltage division effect of stacked transistor configuration with depletion-layer-extended transistors (DETs)”, Ohnakado, T. et al, Solid-State Circuits, IEEE Journal of Volume 39, Issue 4, April 2004 Page(s):577 – 584 [4]Mei-Chao Yeh; Zuo-Min Tsai; Ren-Chieh Liu; Lin, K.-Y.; Ying-Tang Chang; Huei Wang; “Design and analysis for a miniature CMOS SPDT switch using body-floating technique to improve power performance” Microwave Theory and Techniques, IEEE Transactions on Volume 54, Issue 1, Jan Page(s): [5] Single-pole double-throw CMOS switches for 900-MHz and 2.4-GHz applications on p- silicon substrates, Heng-Jung Huang; O, K.K.; Solid-State Circuits, IEEE Journal of,Volume 39, Issue 1, Jan Page(s):35 – 41 [6] 15-GHz fully integrated nMOS switches in a 0.13um CMOS process, Zhenbiao Li; O, K.K.; Solid-State Circuits, IEEE Journal of Volume 40, Issue 11, Nov Page(s):