Advances In Millimeter Wave Measurements

Banded Differential and Pulse Measurements

Agenda

• Enabling Hardware Configurations

• Measurement Capability and Features

• Example of Four Port Device Measurements

• Pulsed Millimeter Wave Measurements

Enabling Hardware

PNA-X (N5242A)

MM-Wave Controllers (N5261A / 2A)

OML MM-Wave Modules

• Direct IF access• Dual spectrally pure sources, low phase noise• Frequency offset measurements• Built-in mm-wave module configuration• Integrated pulse measurement • Differential measurement capability• Multiport calibration capability

• Integrated RF and LO distribution• High current DC power distribution• Accurate control of RF power to modules• Flexibility to attach 2 or 4 banded modules

• 50 GHz to 0.5 THz• Optimized for PNA / PNA-X• Provides T/R and or T only modules• Close proximity to on-wafer DUT

N5261A / 2A Block Diagram

• Rear panel jumper for direct connection of RF to test set

• DC power supply for up to 4 mm-wave modules up to 0.5 THz

• 5 channel IF multiplexing

• ALC enable/disable for RF to module

• LO distribution for up to 4 modules

• Easily re-configured for 2 port support

• Allows for the use of a single and dual Source PNA-X

Agenda• Enabling Hardware Configurations

• Measurement Capability and Features

• Example of Four Port Device Measurements

• Pulsed Millimeter Wave Measurements

Measurement Capabilities• Standard S-Parameter Measurements

– S11……S44• Mixed Mode Measurements

– Differential P1 and P3 – Sdd11, Sds21, Scs21,

• Full 2-Port pulse on Port 1 and 2 • Support up to 0.5 THz mm-wave modules (without external power Supplies)

Feature Set

• New millimeter module configuration interface, requires new firmware update.

• Test set ALC control On/Off• Front or rear panel interconnect of RF to the mm-wave

test set• Presetting system maintains all RF and test set ALC

settings by the user.• Uses the multiport calibration for 4-port.• When used on a 2-port PNA-X requires option 551

Millimeter Module Configuration

• Multiple configurations including a standard PNA configuration

• Selection of supported mm-wave test sets

• Front and rear panel RF configuration for PNA-X

• ALC enable/disable for power control to module and pulse measurements

• Frequency setting for mm-wave modules including multiplier and port frequency

• Selection of PNA-X or external RF and LO sources

Agenda• Enabling Hardware Configurations

• Measurement Capability and Features

• Example of Four Port Device Measurements

• Pulsed Millimeter Wave Measurements

Example of a Four Port Device

Port 3Port 4

Port 1

Port 2

Magic Tee

Magic Tee Characteristics• Sum and difference ports are isolated

• Signals from the difference port are 180º out of phase

• Signals from the sum port remain in phase

• Applications for power combiner and signal division

Single Ended Measurements of a Magic Tee• Magnitude of port 3 and 4 with respect to the difference of port 1 • Isolation between sum and difference ports

Magnitude of port 3 and 4 with respect to the Sum of Port 2

Single Ended Measurements of a Magic Tee• Phase measurement of S32 and S42• Both measurements are in phase with each other

Differential Phase Ports 3 & 4 with respect to port 1

Differential Measurements

Port 3 Port 4

Port 1

Port 2

Port 3 Port 4

Port 1

Port 2

Measurement One: Difference Port SE - BAL Measurement Two: Sum Port SE - BAL

Difference Port SE- Balanced

Port 2+ Port 2-

Port 1

Sum Port Terminated

Sum Port SE- Balanced

Port 2+ Port 2-

Difference Port Terminated

Port 1

Verification of Measurements• Comparison of Single Ended and

Differential measurements

44434333444334334131

44433433444334334131

1413141311

2

1

2

1

2

2

1

2

1

2

22

SSSSSSSSSS

SSSSSSSSSS

SSSSS

Smm

Port 3 Port 4

Port 1

222221

222221

121211

cccdcs

dcddds

scsdss

SSS

SSS

SSS

Single Ended versus Balanced measurement

21413

12

SSSsd

Common Mode

Differential

21413

12

SSSsc

Agenda• Enabling Hardware Configurations

• Measurement Capability and Features

• Example Four Port Device Measurements

• Pulsed Millimeter Wave Measurements

Pulsed Signal in Time and Frequency Domain

fc

Pulse repetition frequency(PRF = 1/PRI)

1/PW

Time domain

Pulse width (PW)

Pulse repetition period (PRP)Pulse repetition interval (PRI)

Carrier frequency (fc)

Measured S-parameters

Frequency domain

Duty cycle = on time/(on+off time)

= PW/PRI

)())()(()( 1 tshahtxtrecttyprf

pw

0 1/prf-1/prft

......*

n(t-n(1/prf))

0 1/prf 2/prf-1/prf-2/prf

......rectpw(t)

0 1/2pw-1/2pwt

x(t)

))(())()(()( sprfshahprfsXspwsincpwsY

))(())(()( sprfshahprfspwsincpwsY

)()()( sprfshahspwsincDutyCyclesY

Mathematical Representation of Pulsed Signal

Pulsed Frequency Domain Spectrum

This is the spectrum of a pulsed signal at a pulse repetition frequency of 1.69 kHz and a pulse width of 7 us.

Pulsed Spectrum

-60

-50

-40

-30

-20

-10

0-2

0000

00

-150

0000

-100

0000

-500

000 0

5000

00

1000

000

1500

000

2000

000

Frequency Offset (Hz)

Pu

lse

d R

ep

on

se

(d

B)

Nulls at 1/pw

Pulsed Frequency Domain Spectrum (Zoom)

This is the same pulsed spectrum zoomed in on the fundamental frequency that is pulsed (center). Notice that the spectrum has components that are n*prf away from the fundamental. In pulse narrowband detection mode, ideally we would want a rectangular filter to filter out everything but the fundamental pulsed frequency.

Pulsed Spectrum(zoomed)

-0.0025

-0.002

-0.0015

-0.001

-0.0005

0

-2000

-1500

-1000

-500 0

500

1000

1500

2000

Frequency Offset (Hz)

Pu

lse

d R

es

po

ns

e (

dB

) Wanted frequency component

First spectral tone at 1.69kHz=prf

Pulsed S-Parameter Measurement ModesWideband/synchronous acquisition

– Majority of pulse energy is contained within receiver bandwidth

– Incoming pulses and analyzer sampling are synchronous(requires a pulse trigger, either internal or external )

– Pulse is “on” for duration of data acquisition

– No loss in dynamic range for small duty cycles (long PRI's), but there is a lower limit to pulse width

Receiver BW

Pulse trigger

Time domain Frequency domain

Pulsed S-Parameter Measurement ModesNarrowband /Asynchronous Acquisition

– Extract central spectral component only; measurement appears CW

– Data acquisition is not synchronized with incoming pulses (pulse trigger not required)

– Sometimes called “high PRF” since normally, PRF >> IF bandwidth

– “Spectral nulling" technique achieves wider bandwidths and faster measurements

– No lower limit to pulse width, but dynamic range is function of duty cycle

IF filter

IF filter

Time domain

Frequency domainD/R degradation = 20*log[duty cycle]

Agilent PNA-X Pulse Enhancements• Key Pulse Features:

– Internal Pulse Generators (option 025)• Up to 4 independent output channels that can be configured to drive internal

components (modulators) or external components• 60 MHz clock frequency(16.7 ns resolution)

– Internal Pulse Modulators• Can option with either 1 (option 021) or 2 (option 022) modulators (One per

source)• PW < 100 ns (rise time < 5 ns)

– Time resolution on receiver is less than 100 ns (20 ns typical) in narrowband mode– Enhanced Narrowband Detection Technique

• Substantial increase in measurement sensitivity and speed over current narrowband technique based on new patented pulse receiver architecture and algorithms

– Wideband mode current detection BW is 600 kHz (work is being done to increase this detection BW)

– Improved UI

One Box Test Solution

New

New

New

New

PNA-X Pulse Hardware Enhancements• The New PNA-X can be configured in a number of different pulse configurations

(more option information can be found in the PNA-X configuration guide):– 2-Port, 1 Source, 1 Modulator

• Provides pulse stimulus in one direction only (option 021)• Can use internal (option 025) or external pulse generators

– 2 or 4-Port, 2 Source, 1 or 2 Modulators• Provides pulse stimulus in one (option 021) or two (option 021 and 022) directions• Can use internal (option 025) or external pulse generators

New PNA-X Pulse Detection Techniques• The New PNA-X has added significant enhancements in the narrowband

detection mode using the narrowband IF path:– Digital Filter Nulling (Patent Pending)

• The digital filter nulls can be placed precisely on the pulse spectral lines since their location is known when using the internal pulse generators.

– Crystal Filter (Invention Disclosed)• There is a narrowband crystal filter (BW = 30 kHz) in the narrowband

pulse IF path which is used to increase the narrowband pulse mode sensitivity.

– SW Gate (Patented)• When using HW IF gating and internal pulse generation, we know the on

and off times of the gate (signal) precisely. Since the off times of the gate contain undesirable noise and/or residual gate isolation, the algorithm can replace the off times with an ideal off state (i.e. zeros) thereby improving the receiver sensitivity.

Pulsed Millimeter Wave Measurements• Support’s NB and WB Pulse• Configure the mm-wave system for modules

connected• Turn off ALC in the test set• Then start either Narrow or WB Pulse application• Configure the Pulse RF and Gate settings

RF ALC

Control

PNA-X Pulse Application – Main FormThe current pulse application (option H08) has been modified to include the use of the internal pulse generators and pulse modulators.

PNA-X Pulse Application – Pulse Profile

New PNA-X solution is substantially faster due to:

- Virtually no communication overhead using internal pulse generators

- Increased measurement sensitivity allows use of wider IF BW’s

77 GHz CW Pulse Profile

Automotive Radar Application Measurements

38-76 GHz Multiplier MMIC

76 GHz GsAs PIN Multithrow Switch

MMIC

19 GHz AMP

19-38 GHz Multiplier

76 GHz Mixer

LPF

0.01 uF

19-19.25 GHz OSC

Rad

iated P

ow

er

External Bandpass Filter

Autonomous Cruise Control Transceiver Module

Pulsed Millimeter Wave System Measurements

• Complete S-Parameter Measurements of 76 GHz PIN Switch

• Isolation between TX and RX channels

Test Set Ordering Configuration • N5262A (4-Port Test Set)

– Option 501 - Set of 4 RF, LO, IF and DC cables* 1.2 meter– Option 502 - Set of 4 RF, LO, IF and DC cables 2 meter– Option 503 - Set of 4 RF, LO, IF and DC cables 3 meter– Option 504 - Set of 4 RF, LO, IF and DC cables** 5 meter– Option 102 - Test interconnect for 2-Port PNA-X– Option 104 - Test Interconnect for 4-Port PNA-X

*Default for RF, LO and DC cables ** Not recommended for use with 325 or 500 GHz Modules (Loss)

• N5261A (2-Port Test Set)– Comes with standard 48 inch RF, LO, IF and DC cables– Option 102 – Test interconnect for 2-Port PNA-X– Option 104 – Test Set interconnect for 4-Port PNA-X

Agenda• Enabling Hardware Configurations

• Measurement Capability and Features

• Example Four Port Device Measurements

• Pulsed Millimeter Wave Measurements