Seminar Aerospace andAgilent Defense Symposium 2010 Seminario Agilent Dispositivi non lineari: una breve introduzione dei Parametri X e del Nonlinear Vector Network Analyzer Seminar Aerospace andAgilent Defense Symposium 2010 Evolution of the Tools & Measurements Patchwork S-Parameters TOOLS: SS & Oscilloscope Grease pens and Polaroid cameras Slotted line Power meter MEASUREMENTS: Bode plots Gain SWR Scalar network analyzers Y & Z parameters TOOLS: Vector Network Analyzer MEASUREMENTS: Gain Input match Output match Isolation Transconductance Input capacitance S-Parameters + Figures of Merit TOOLS: NA SA/SS/NFA Power meter Oscilloscope DC Parametric Analyzer MEASUREMENTS: Gain compression, IP3, IMD PAE, ACPR, AM-PM, BER Constellation Diagram, EVM GD, NF, Spectral Regrowth ACLR, Hot “S22” NVNA + X-Parameters Seminar Aerospace andAgilent Defense Symposium 2010 Agenda • Steps and Architectures in Network Analysis • Nonlinear VNA and X-Parameter 3 Seminar Aerospace andAgilent Defense Symposium 2010 Classic VNA Block Diagram 4 Seminar Aerospace andAgilent Defense Symposium 2010 Network Analysis Step1: S Parameter (1965) Linear or nonlinear networks operating with signals sufficiently small to cause the networks to respond in a linear manner, can be completely characterized by parameters measured at the network terminals without regard to the contents of the networks. - Relatively easy to obtain at high frequencies (measure voltage traveling waves with a vector network analyzer don't need shorts/opens which can cause active devices to oscillate or self-destruct); - Relate to familiar measurements (gain, loss, reflection coefficient ...); - Can cascade S-parameters of multiple devices to predict system performance; - Can compute H, Y, or Z parameters from S-parameters if desired; - Can easily import and use S-parameter files in our electronicsimulation tools. • K. Kurokawa, ‘Power Waves and the Scattering Matrix,IEEE Transactions on Microwave Theory and Techniques, Vol. MTT-13, No. 2, March, 1965. 5 Seminar Aerospace andAgilent Defense Symposium 2010 Modern VNA Block Diagram Receivers RF jumpers Mechanical switch rear panel +28V (for noise source) Pulse generators Signal combiner + - 1 2 3 4 Source 2 Source 1 OUT 1 R1 OUT 2 OUT 2 LO To receivers Pulse modulator 10 MHz 3 GHz 326.5 GHz Pulse modulator A R3 Test port 1 Impedance tuner for noise figure measurements 6 OUT 1 Noise receivers C Test port 3 R4 R2 D Test port 4 B Test port 2 Seminar Aerospace andAgilent Defense Symposium 2010 Network Analysis Step2: X Parameter (2007) Agilent Technologies developed X-parameters. has X-parameters represent and analyze the nonlinear behavior of RF components in a much more robust and complete manner. As an extension of S-parameters under large-signal operating conditions, they are driven into saturation (the real-world operating environment) and then measured under these conditions. 7 Seminar Aerospace andAgilent Defense Symposium 2010 Agenda • Steps and Architecture in Network Analysis • Nonlinear VNA and X-Parameter 8 Seminar Aerospace andAgilent Defense Symposium 2010 Designing a Power Amplifier (1) The designer wants to drive the amplifier into the nonlinear region (large signal) to get the maximum output power as well as to extract the maximum efficiency 9 Seminar Aerospace andAgilent Defense Symposium 2010 Designing a Power Amplifier (2) Under large-signal conditions there are nonlinear effects: - distort waveforms (time domain), - harmonics, inter-modulations… (frequency domain). S-parameters can only analyze and model the linear behavior. 10 Seminar Aerospace andAgilent Defense Symposium 2010 Current Techniques for a Non-linear Device Data sheets for amplifiers often have both linear and non-linear information Non-linear parameters Linear parameters Pout vs Pin IMD S=parameters PAE P1dB 11 Seminar Aerospace andAgilent Defense Symposium 2010 A [new]-parameter file like a 3-D CAD file The “library” contains all the necessary information [new]-parameter 3-D file 12 [new] Parameter file S-parameter Seminar Aerospace andAgilent Defense Symposium 2010 X-parameter Concept 13 Seminar Aerospace andAgilent Defense Symposium 2010 X-parameters come from the Poly-Harmonic Distortion (PHD) Framework Port Index 14 Harmonic (or carrier) Index Seminar Aerospace andAgilent Defense Symposium 2010 Harmonic Superposition Principle • In general, we are working under large-signal, nonlinear operating conditions. The superposition principle (parameters of individual components are sufficient to determine the parameters of any combination of those components) is not valid. • In many practical cases (power amplifiers stimulated with a narrowband input signal) there is only one dominant large-signal input component present (A11). All other input components (the harmonic frequency components) are relatively small. In that case, we will be able to use the superposition principle for the relatively small input components. • This is called the harmonic superposition principle. 15 Seminar Aerospace andAgilent Defense Symposium 2010 Harmonic Superposition Principle • (to keep the graph simple) Only consider the presence of the A1m and B2n components (neglect the presence of the A2m and B1n). • Case A11 <> 0. A1m and B2n are indicated by black arrows. Note harmonic components for the B2n components. • Leave the A11 the same and add a small A12 component (second harmonic at the input). This will result in a deviation of the output spectrum B2 The same holds for a third harmonic and a fourth harmonic. • The harmonic superposition principle holds when the overall deviation of the output spectrum B2 is the superposition of all individual deviations 16 Seminar Aerospace andAgilent Defense Symposium 2010 The [new] X-parameter Classic S-parameters: only linear behavior and ignore nonlinear behavior (harmonic, intermodulation, higher order mixing effects). X-parameters capture linear behavior and linearize nonlinear behavior about a large signal operating point (LSOP). NVNA measures X-parameters stimulating the DUT with a single large tone at port 1 and, in the same time, injecting additional small tones at both ports 1 and 2 at all harmonics of interest. At least two phase-offset small tones must be injected at each port/frequency of interest in order to extract the corresponding X-parameters. 17 Seminar Aerospace andAgilent Defense Symposium 2010 Source 1 Source 2 (standard) OUT 2 OUT 1 OUT 1 J11 J10 J9 SW1 R1 J8 J4 SW3 A R4 Test port 1 Test port 3 Rear panel J2 J1 SW2 R2 D 35 dB 65 dB J3 SW4 C 35 dB 65 dB OUT 2 J7 R3 10 MHz Internal Reference B 35 dB 65 dB Test port 4 65 dB Test port 2 Measurement phase reference To port 1 or 3 for calibration Calibration phase reference Injecting a large tone at port 1 18 35 dB Seminar Aerospace andAgilent Defense Symposium 2010 Source 1 Source 2 (standard) OUT 2 OUT 1 OUT 1 J11 J10 J9 J8 OUT 2 J7 SW1 J4 SW3 Test port 1 D 35 dB 65 dB Test port 3 B 35 dB 65 dB 65 dB 35 dB Test port 2 Test port 4 To port 1 or 3 Injecting a drive and probe tone at port 1 19 J1 R2 C 35 dB J2 SW2 R4 A 65 dB Rear panel SW4 R3 R1 J3 Ext Source in Calibration Phase Reference Measurement Phase Reference Seminar Aerospace andAgilent Defense Symposium 2010 Source 1 Source 2 (standard) OUT 2 OUT 1 OUT 1 J11 J10 J9 J8 OUT 2 J7 SW1 J4 SW3 Test port 1 D 35 dB 65 dB Test port 3 B 35 dB 65 dB 65 dB 35 dB Test port 2 Test port 4 To port 1 or 3 Injecting a drive tone at port 1 and probe tone at port 2 20 J1 R2 C 35 dB J2 SW2 R4 A 65 dB Rear panel SW4 R3 R1 J3 Ext Source in Calibration Phase Reference Measurement Phase Reference Seminar Aerospace andAgilent Defense Symposium 2010 -3f0 -2f0 -f0 DC aj2* Measuring B2,3 which is the Port2 output value at 3rd harmonic (3f0). X(F)2,3 … + X(S)23,gh … + X(T)23,gh … 21 f0 2f0 3f0 aj2 4f0 5f0 Seminar Aerospace andAgilent Defense Symposium 2010 On-frequency 22 Upper sideband Lower sideband Seminar Aerospace andAgilent Defense Symposium 2010 Understanding X-parameter display X-parameters: XFp, XSpq and XTpq Both the p and q terms are described by a Port and Harmonic combination. For example: XS21,13 Parameters for each possible (port, harmonic) selection of p For example: for p=(2,1) , and assuming 3 harmonics of interest: XF21 (XS21,11),(XT21,11) (XS21,12), (XT21,12) (XS21,13), (XT21,13) (XS21,21), (XT21,21) (XS21,22), (XT21,22) (XS21,23), (XT21,23) For a 2-port device, with 3 harmonics of interest at each port: - there are 6 possible (port, harm) combinations for p. - each combination yields 13 parameters, 23 Total of 6*13 78 X-param Seminar Aerospace andAgilent Defense Symposium 2010 X-parameters reduce to S-parameters dB 40 20 X (F ) 21 [ X 21( F ) ( A11 )] / | A11 | | A11 | (S ) X 21,21 0 (S ) X 21,21 ( A11 ) | A11 | 0 | A11 | 0 | A11 | 0 s21 s22 -20 -40 -60 -25 X -20 -15 -10 -5 |A11| (dBm) 24 (T ) X 21,21 ( A11 ) (T ) 21,21 0 5 10 0 Reduces to (linear) S-parameters in the appropriate limit Seminar Aerospace andAgilent Defense Symposium 2010 25 X-parameters is actually a large data library -- X-param is measured with many variables -X-param one page one chapter [X]p1 [X]p,f1 [X]p2 [X]p,f2 [X]p3 Various Power [X]p,f3 Various Frequencies Measurement takes from tens of minutes to a several hours depending on the size of the “library” 26 one book [X]p,f,Vg1 [X]p,f,Vg2 [X]p,f,Vg3 Various gate voltages one series of books one bookshelf [X]p,f,Vg,Vd1 [X]p,f,Vg,Vd,z1 [X]p,f,Vg,Vd2 [X]p,f,Vg,V,z2 [X]p,f,Vg,Vd3 [X]p,f,Vg,Vd,z3 Various drain voltages Various load Z one library = one X-param file [X]p,f,Vg,Vd,z Seminar Aerospace andAgilent Defense Symposium 2010 Example of an X-Par .xnp file 27 Seminar Aerospace andAgilent Defense Symposium 2010 Calibration Three step calibration process: 1) SOLT or TRL style calibration 2) Absolute receiver calibration using a power meter/sensor 3) Receiver phase calibration using Agilent’s new comb generator. 28 Seminar Aerospace andAgilent Defense Symposium 2010 NVNA System Configuration Amplitude Calibration X-Parameter extraction/multi-tone source Vector Calibration Phase Calibration Standard PNA-X Network Analyzer 29 Phase Reference Seminar Aerospace andAgilent Defense Symposium 2010 Measurement Display 30 Seminar Aerospace andAgilent Defense Symposium 2010 1. Nonlinear Component Characterization * Absolute amplitude Frequency Domain and cross frequency relative phase of measured spectra traceable to standards lab * Data displayed in frequency, time and power domains: - ‘a’ and ‘b’ waves versus sweep domain - V and I versus sweep domain - V versus I, I versus V 31 Seminar Aerospace andAgilent Defense Symposium 2010 1. Nonlinear Component Characterization * Absolute amplitude Time Domain and cross frequency relative phase of measured spectra traceable to standards lab * Data displayed in frequency, time and power domains: - ‘a’ and ‘b’ waves versus sweep domain - V and I versus sweep domain - V versus I, I versus V 32 Seminar Aerospace andAgilent Defense Symposium 2010 1. Nonlinear Component Characterization * Absolute amplitude and cross frequency relative phase of measured spectra traceable to standards lab * Data displayed in frequency, time and power domains: - ‘a’ and ‘b’ waves versus sweep domain - V and I versus sweep domain - V versus I, I versus V 33 Power Domain Seminar Aerospace andAgilent Defense Symposium 2010 1. Nonlinear Component Characterization * Absolute amplitude and cross frequency relative phase of measured spectra traceable to standards lab * Data displayed in frequency, time and power domains: - ‘a’ and ‘b’ waves versus sweep domain - V and I versus sweep domain - V versus I, I versus V 34 Customize Domain: V/I Seminar Aerospace andAgilent Defense Symposium 2010 2. X-parameter measurement Frequency Domain 35 Seminar Aerospace andAgilent Defense Symposium 2010 2. X-parameter measurement Power Domain 36 Seminar Aerospace andAgilent Defense Symposium 2010 Three-port X-parameter Two-tone X-parameter Pulse envelope domain 37 Seminar Aerospace andAgilent Defense Symposium 2010 Three-port X-parameter measurements 38 Seminar Aerospace andAgilent Defense Symposium 2010 Two-tone X-parameter measurements 39 Seminar Aerospace andAgilent Defense Symposium 2010 Nonlinear pulse envelope domain Configuration, Cal and Meas (Waves and Harmonics): menu Utility > Measurement Domain… > Envelope Domain 40 Seminar Aerospace andAgilent Defense Symposium 2010 NVNA and ADS 41 Seminar Aerospace andAgilent Defense Symposium 2010 Don’t you have this problem? device model model takes time and is not accurate Modeling: I need a couple of months Transmitted Spectrum Transmitted Spectrum 0 -10 -20 -20 Spectrum_out -40 Spectrum_out I want to start my design now! 0 -60 -80 simulated ACPR -30 -40 -50 -60 -100 -70 -120 -2.5 -2.0 -1.5 -1.0 -80 -0.5 0.0 freq, MHz 0.5 1.0 1.5 2.0 2.5 -2.5 -2.0 -1.5 -1.0 -0.5 measured ACPR 0.0 0.5 1.0 1.5 freq, MHz My simulation gave me a great answer but the reality is… 42 2.0 2.5 Seminar Aerospace andAgilent Defense Symposium 2010 X-parameter enables 3 activities to run in parallel before process dev. amplifier desing modeling module desing after process dev. [X] amp designers can start design without waiting for the model Meas amplifier design [X] [X] Sim Meas module design 43 module designers can start design with the simulated X-param then with the measured X-param New technologies like GaN Seminar Aerospace andAgilent Defense Symposium 2010 NVNA and ADS 44 Seminar Aerospace andAgilent Defense Symposium 2010 S Parameter S Parameter NA ADS 45 Seminar Aerospace andAgilent Defense Symposium 2010 Component Char. Component Char. NVNA ADS ____ ____ 46 -20dBm Input 0dBm input Seminar Aerospace andAgilent Defense Symposium 2010 X Parameter X Parameter NVNA ADS 47 Seminar Aerospace andAgilent Defense Symposium 2010 ADS S-parameter vs X-parameter S-parameter S-par not valid X-parameter ____ ____ 48 -20dBm Input 0dBm input Seminar Aerospace andAgilent Defense Symposium 2010 ADS S-parameter vs X-parameter Transmission Reflection Output Voltage S-par not valid S-par X-par ____ ____ 49 -20dBm Input 0dBm input Seminar Aerospace andAgilent Defense Symposium 2010 Power Amplifier Design 50 Seminar Aerospace andAgilent Defense Symposium 2010 X-Parameter Example on GaN amplifier • 32 Watt 1.2 GHz GaN (Gallium Nitride) Amplifier, - PAE (Pout-Pin)/(Vdc*Idc) on datasheet: 55% 1. Measured with PNA-X/NVNA this amplifier and obtained X-parameters. 2.Loaded the measured X-parameters into ADS 3.Performed simulation in ADS: - ADS predicted an PAE of 75%, by using optimum output impedance matching circuitry on 1s, 2nd and 3rd harmonic. 4.Realized PCB for this amplifier, following the ADS suggestion for optimization 5.Measured the PCB (with amplifier mounted on it) with PNA-X/NVNA - Actual measured PAE was 75% - Matches ADS prediction - By using this X-par approach we could achieve 20% better PAE. 51 Seminar Aerospace andAgilent Defense Symposium 2010 NVNA X-parameter System – Power budget (120W) Application Note 1408-19: High Power Amplifier Measurements using Agilent’s Nonlinear Vector Network Analyzer 52 Seminar Aerospace andAgilent Defense Symposium 2010 High Power X-parameter Measurement System 53 Seminar Aerospace andAgilent Defense Symposium 2010 Component manufacturers start to make X-Parameters available to their customers USA Canada UK Germany France Netherlnand Sweden Turkey Poland Romania Japan Taiwan China Korea Agilent is using X-parameters for the internal design and also selling ICs to the external customers with X-parameter files. 54 Seminar Aerospace andAgilent Defense Symposium 2010 Summary The NVNA nonlinear measurements with full match correction and accurate amplitude and cross frequency relative phase information provide a new standard in accuracy and insight of the behaviors of nonlinear components 55