Test Challenges in MMICs, RFICs and High Speed Analog Circuits. Dror Regev

Transcription

1 Test Challenges in MMICs, RICs and High Speed Analog Circuits

2 Agenda Presto-Engineering Challenges in Wide-Band and mm-wave Test MMIC/RIC Probing at high mm-wave requencies Standard Automatic Tester limitations mm-wave DUT docking & interfacing challenges Solution Approaches & RIC Test Economics requency conversion technical consideration example

3 160 MHz Challenges in Wide-Band and mm-wave Test Ever growing demand for Data Rate, drive extended BW and req ac Wi-i 80.11ad Wi-Gig 1.8 GHz PTP 4G/LTE 500 MHz 5 GHz 60 GHz E-Band Wide Band multi-carrier modulation schemes requiring high EVM. Reduced Dynamic Range, impairments worsen. Thermal loor, N, TX Power, Linearity, Phase Noise, Ripple & Reflections

4 MMIC/RIC mm-wave requencies GSG probe is dispersive and radiates energy or good S-par calibration, 30dB isolation between probes is required. At 150um pitch, calibration substrate BW is not guaranteed beyond 65-70GHz but perform reasonably up to E-band frequencies. λ/0 GSG Probe pitch, should be maximum pitch for accurate testing. Hence 150um pitch for ε r =1 can perform to ~ 100GHz. However, DUT ε r will affect test accuracy as : 43um GSG probe is needed for best performance at ~ 110GHz.

5 MMIC PA E-band (71-86GHz) CW Gain and Saturation Wafer Level 50um Thick GaAs wafer on insulator carrier pose Thermal Stress -> Pulse? Recent market drive towards full S-par test.

6 RIC Transceiver E-band (71-86GHz) 500MHz BW wafer level RX & TX EVM tests Employing WB requency Converters to/from E-band

7 Standard Automatic Tester limitations Max I/O frequency limited to 6 or 1GHz!. Needs requency Extension to drive/test higher frequencies. Instantaneous BW limited ~ 00MHz.

8 mm-wave DUT docking & interfacing challenges Sockets are limited in frequency (<30GHz) and pose high parasitic and no perfectly consistent mm-wave contact resulting test errors. Many 60 GHz DUTs are integrated with antennas. SiBEAM WHD module (Ali M. Niknejad) VSWR of socket and TL degrade Test latness. De-embedding?. 1nH Serial = jωl j00 ohm 50pH Serial j10 ohm Path Loss over the air 1meter/60GHz) Antennas Crosstalk and Multipath especially for multisite

9 More Challenges in WB and mm-wave Test Link Budget Example 1GHz 60GHz: RX DUT Noise loor: P 1GHz BW = log N(6dB )= -78dBm 1 db out comp. 60GHz converter (no PA): -0dBm TX Back Off: 8dB Maximum TX power: -8dBm TX + DUT Antenna Gains: 0dB 1 Meter path loss: 68dB Total over the air (OTA) loss: 48dB RX DUT Signal Level: P Recieved Signal = -8 dbm - 48= -76dBm Conclusion: Such stand alone converter can not support WB EVM testing OTA.

10 Solution Approaches & RIC Test Economics requency extension NB or WB: Convert (or multiply) I/O requency of automatic tester, signal generator and test instruments to/from mm-wave frequency. UWB on load board E-Band converter 60GHz IQ converter 60GHz Transceiver Testing Modules integrated with Antennas : Employ wafer probing when relevant Economic OTA testing or Contact less probing.

11 requency conversion technical consideration IQ Conversion 101: Ideal Up-Conversion BB I f LO f LO 0 0 /90 0 I 1 BB Q I f LO Ideal Down-Conversion I+Q BBI = Sin(ω LO t) Cos (ω LO ω BB )t I Q Cos (ω LO + ω BB )t = I Sin (ω BB)t + BBQ = Cos(ω LO t) I+Q I Q = Q Cos (ω BB)t +. Cos (ω LO ω BB )t Cos (ω LO + ω BB )t = = BB I f LO BB Q 0 0 /90 0 f LO I + Q f LO Q I

12 requency conversion technical consideration Transceiver requency Plan using a Single Synthesizer: LO1, LO Generation: = LO1 = LO Popular case : M=, N=1. LO1 LO 3 R 3 LO R LO1 0 GHz 3 LO R LO1 0 GHz

13 requency conversion technical consideration Ideal performance of 1/3, /3 frequency plan: BB I f LO1 = f R /3 0 0 /90 0 I 1 f R /3 R=1 LO +1 I WB Signal BB Q I f LO = *f LO1 f I =f R /3 f 3f LO1 TX 11 =desired output = Cos(ω LO t) = I+Q 4 - I Q 4 I+Q Cos (ω LO ω LO + ω BB )t + Cos (ω LO + ω LO ω BB )t Cos (ω LO ω LO ω BB )t + Cos (ω LO + ω LO + ω BB )t = I+Q 4 Cos (3ω LO ω BB )t +. - I Q 4 ω = 3 ω LO1 Cos (ω LO ω BB )t I Q Cos (ω LO + ω BB )t Cos (3ω LO + ω BB )t +

14 requency conversion technical consideration Inter-Modulations in Mixers: IMD nm = ±nfl O ± mf R Where n, m integers 0, 1,,3 Special interest should be paid for IMD products with m=1 which inherently have higher power levels TX 1 = Iinter-modulation IMD 1 = In Band Impairment= I+Q a Cos(4ω LO t) Cos (ω LO ω BB )t I Q Cos (ω LO + ω BB )t = Cos (3ω LO + ω BB )t + Cos (5ω LO ω BB )t - I Q Cos (3ω LO ω BB )t + Cos (5ω LO + ω BB )t a I+Q 4 4 ω = 3 ω LO

15 requency conversion technical consideration M1 Impairment in Heterodyne 1/3, /3f 0 : Up converter (as well as Down converter) mixer present: significant LO -1 R inter-modulation product around the same center frequency. WB Signal BB I f LO1 = f R /3 0 0 /90 0 I 1 f R /3 R=1 LO +1 I IM 1 = LO -1 I a f R Intermod. BB Q I f R /3 f LO = *f LO1 a- Mixer IM 1 suppression can be improved to a certain level by improving Balun Balance

16 Summary High mm-wave wafer probing relevant when: Chip ASP and performance is critical as with PAs. Packaging or final module expensive as with MCMs. Socket testing is limited today to ~ 30GHz OTA testing is good for characterization and pose challenges in HVM environment. Contact less probing has potential advantages.