Integrated Solutions for 5G Frequency-Division and Full Duplex Systems Prof. Emanuel Cohen Students: Nimrod Ginzberg, Yanir Schwartz, Iliah Konstantinovsky, Roy Weiss, Pavel Vilner, Tomer Gidony Technion High Frequency Integrated Circuits

Outline Introduction and Motivation TX+TX systems TX+RX systems – flexible FDD Full Duplex Summary & Conclusion

Capacity enchantments options in existing spectrum : Carrier aggregation at TX and RX (TX+TX, RX+RX) Flexible Frequency division multiplexing FDD (TX+RX) Full duplex : Simultaneous TX and RX at same frequency.

The Multi-band cellular radio

The Carrier Aggregation Challenge Intra-band contiguous CA Intra-band non-contiguous CA From when do we have carrier aggregation? Intra band – within the same band two channels. Inter bands – between two different bands. Coming from operators demand as they release 2G bands looking ahead into 4G. Still having tough time to be presented into the market but it is on the trand Inter-band CA

FDD system TX + TX

Diplexer-Free Dual-Band Transmitter for Carrier Aggregation Signals

Digital Predistortion on Concurrent Noncontiguous Transmitters Using 2D Piecewise Vector Decomposition Tomer Gidoni, Emanuel Cohen ”Digital Predistortion on Concurrent Noncontiguous Transmission Using 2D Piecewise Vector Decomposition”. –COMCAS17

Simulation and testing of TX+TX Nimrod Ginzberg, Emanuel Cohen ” Linearization Technique of Diplexer-Free Transmitter for Carrier Aggregation Signals” - COMCAS17

FDD systems TX + RX

Multi-band (TX+RX) FDD Directions

Potential Integration of Tunable Diplexer “Splitter” with high isolation Mohyee Mikhemar ”Multiband RF Antenna Duplexer on CMOS Design and Performance” – JSSC 2013

Mm-Wave Autotransformer Performance Wideband isolation >30dB for 25GHz BW around 60GHz IL about 1-1.5dB above theoretical limit Tuning elements overcome process variations

N Path Filter Topology Downconvert + LPF + Upconvert = BPF

Potential solution (TX+RX) RX Npath filter Wideband noise from TX leaks to RX High swing TX reaches RX Create a notch for the noise from TX to RX Using Npath filter design

Npath Tunable Duplexer Implementation

N-path Tunable Duplexer simulation results TX RX Tx [dBm] Isolation [dB] IL [dB] One Resonator Two Resonators Up to 24dBm with no filter degradation

Large array & FDD challenge Low cost dynamic backhauling Create a phased array with shared TX/RX antenna space

FDD antenna research Interleaved TX-RX arrays example: DGS example: Cross pol isolation with scan

Interleaved TX-RX Performance Limit inf Array Pavel Vilner, Emanuel Cohen ” Power Balance Analysis of an Infinite Equispaced Linear Array Composed of Two Alternating Types of Elements”. – COMCAS17

Full Duplex (FD) system Simultaneous Transmit & Receive (STAR)

Full-Duplex (FD) Wireless

Full-Duplex Challenges Leakage paths require large number of taps Calibration Accuracy Amp+/-0.1dB Phase +/-0.5deg NF

J. Zhou et al, ISSCC 16

“Active” Circulator based on 90o NRPS* Ferrite Circulator Large ( typically >1x1 cm2 ) Cannot be integrated into an IC N. Reiskarimian and H. Krishnaswamy, nature communications 16 Assuming a signal is injected from the transmitter Constructive interference at the Ant port 1 2 3 (-90o) 1 2 3 (-90o) Destructive interference at the Rx port (*) Only the LO Driver consume power *Non-Reciprocal Phase Shifter

Integrated Circulator Improved Performance NRPS Test-Chip High impedance loads at high LO harmonics are used to reduce insertion losses Designing low PN LO (specifically, eliminating any uncorrelated PNs) to reduce NF Roy Weiss, Emanuel Cohen ” Low Loss Integrated N-Path-Filter-Based Circulator” COMCAS17

4-Phase-Pulser Block Diagram clk1 clk2 clk3 clk4 CLK 0-180⁰ Splitter Frequency Divider CLKp CLKn I+ Q+ I- Q- VC VB (1) (2) (3) Monte Carlo Sim. Retiming for reduced jitter Timing alignment for process robustness Configurable fast divider for 1-12GHz operation

Summary and Conclusions TX+TX system based on 2D DPD and analog injection can reduce cross modulation and intermodes TX+RX system based on EBD can work up to mmw and show wideband isolation (20dB for 50-75 GHz range) – IL about 4- 4.5dB TX+RX system based on integrated Npath circuits can achieve more than 20dB isolation with around 1-2dB of IL penalty for few GHz range Full duplex systems can be implemented based on integrated Npath circulator with IL of ~1dB and 20dB isolation at 2GHz

Thank You