Saturday, 3 December 2016

Australia, Singapore and Malaysia: How to make an IC


Left Melbourne on the Overland train to Adelaide. Very impressed with Adelaide which is a beautiful city with an interesting history. For more see my blog


Among the famous people of Adelaide I found the bronze heads of William and Lawrence Bragg, the only father and son to win a joint Nobel Prize, for virtually creating the science of X-ray crystallography. Not so famous outside their field, they developed the science that enabled Franklin, Crick and Watson to work out the structure of DNA



William Bragg (Father)
Lawrence Bragg (son)


And the rest is History
But if you are interested in microelectronics, X-ray crystallography was key to understanding and developing semiconductor materials such as silicon. No crystallography, no selfies!

And crystallography plays a huge part in  identifying and classifying minerals, which forms a major section in the South Australian Museum.


The mining sector currently contributes around 8.5% to Australia’s GDP and it would be far less efficient without crystallography.


Spent an enjoyable day discovering some of the wines of the McLaren Vale close to Adelaide. And, yes, there is even a link between crystallography and wine as shown in the article “On wine, chirality and crystallography”.

From Adelaide I took the Indian Pacific Train across 2655km of mostly empty Australia, quite an experience, and met up with friends and enjoyed a fantastic time in Perth, another beautiful city.


The Indian Pacific making its way across Australia
Travelling through the Outback

The Bell Tower in Per

Perth























From Perth it was flight back to Singapore and then on to Penang. 

Having got onto the subject of crystallography let’s look at how we turn sand, or quartz into microchips. See Video below




Some more YouTube videos on the topic


Tuesday, 1 November 2016

Canberra, Sydney and on to Melbourne. RF Testing at Wafer level


Canberra

Couldn’t get over how spread out and apparently quiet Canberra is. Yes, it has the public buildings, parliament, museums etc  but most of it feels distinctly suburban. After two nights in Sydney, arrived in Melbourne  to find that November 1st is Melbourne Cup  Day and almost everyone is dressed up to the nines and heading off to the races. I watched it on the big screen in Federation Square. 

Canberra: Swan on the Lake

Canberra: Parliament House

Canberra: National Museum of Australia

Canberra: National Museum of Australia

Canberra: National Museum of Australia

National Museum of Australia A History of the World in 100 Objects
Object 20  
Ramses II, Temple of Khum c.1280 BCE


A History of the World in 100 Objects
Object 101 Wireless LAN test and measurement System
RF gets in somewhere! 

More RF!
Canberra Deep Space Communication Complex:
Dish DSS
-43 (70-metre)

 Deep Space Station 46 (DSS-46).
Now decommissioned, it was originally located at the Honeysuckle Creek Tracking Station and 
is famous for being the antenna which received and relayed the first TV images of Neil Armstrong making that one small step on the Moon in 1969



No connection to RF.
Paterson's curse is a pretty, innocent looking, flower invading Australia's grasslands
Cooma cottage in Yass, near Canberra 


Queen Victoria in front of her building in Sydney

Queen Victoria Building in Sydney
And now for RF Testing at Wafer level 
Why?
          Often needed during development
          Eg to measure TSV performance or integrated passive components
          Move to advanced packaging solutions, eg WLCSP, has meant that measurements that could previously be done at final package test are now needed at wafer level
          Wafer and die testing using a probe station  is fairly straightforward at low frequencies
          Not so easy at MHz and above


Cannot use conventional probes at > Mhz frequencies






Monday, 24 October 2016

Berry New South Wales and How to measure S Parameters

24th October 2016


Berry, New South Wales. Lovely little town surrounded by beautiful countryside.

Great Southern Hotel in Berry

Traditional House in Berry

The Old Post Office

All Roads Lead to Berry
y

Drawing Room Rocks

View from Drawing Room Rocks


Measuring S Parameters

  • S11 and S21
  • Measure magnitude and phase of incident, reflected and transmitted voltage signals
  • Output is terminated in a perfect matched impedance Zo
  • (Load that equals the characteristic impedance of the test system)
  • Matched load impedance ensures no reflection
  • S11 is equivalent to the input complex reflection coefficient or impedance of the DUT 
  • S21 is the forward complex transmission coefficient. 
  • Can measure S22 and S12 by placing source at port 2 and terminating port 1 in a perfect load 
  • For packaging applications we are usually only interested with magnitudes, not phase, and can assume linear behaviour
Key Components 

  • Source for stimulus
  • Signal-separation devices
  • Receivers that down convert and detect the signals
  • Processor/display for calculating and reviewing the results

Output from Network Analyser



Need Test Fixtures

  • Making quality RF measurements on devices with standard coaxial connectors is relatively easy. 
  • Accurate measurements can be made using commercial calibration kits and standard error-correction routines found in most network analyzers 
  • Devices without connectors are tough 
  • Test fixture is needed to provide RF compatible electrical connection between the device and test equipment 
  • In-fixture calibration standards are often required to achieve acceptable accuracy 
  • Also mechanical constraints



Monday, 17 October 2016

Penang to Singapore to Sydney to Berry NSW and S Parameters for RF Packaging

18th October 2016


From Penang to Singapore to Sydney to Berry, New South Wales. A busy couple of weeks which is why the blog got delayed. 

Buddy Bears in Penang, USA, UK and UAE

Moldova has a sense of humour

Holland

Uzbekistan


Coming in to land in Sydney

Iconic Opera House

Iconic Bridge


Bigfoot to go up Coolangatta "Mountain" near Berry NSW

Shoalhaven River from Coolangatta Mountain

Ever wondered what those mysterious S Parameters are? 
Why do they keep on showing up in RF Packaging?

The “S” stands for “scattering”
Probably the most widely used measurements for RF packaging
Can be used to characterise the RF performance of a “black box” without knowing what is inside it
Why use S-parameters? 
Relatively easy to measure at high frequencies
Can measure voltage traveling waves with a vector network analyzer
Relate to familiar measurements (gain, loss, reflection coefficient etc) 
Most importantly  for RF package design and simulation S-parameters are easily imported and used for circuit simulations in electronic-design automation
S-parameters are the shared language between simulation and measurement
The Scattering (S)  Matrix
  • Mathematical construct that quantifies how RF energy propagates through a multi-port network 
  • Enables a complex network to be described as a simple "black box“ 
  • For RF signal incident on one port, some fraction is reflected back out of the same port, some of it goes into that port and exits from one or more other ports 
  • It may be amplified or attenuated 
  • If the network has N ports the S-matrix will have N2 coefficients (S-parameters) 
  • Each S parameter represents one possible input-output path.
S Parameters for two port network
  • Note that S21 = b2/a1 is a measure of the output at port 2 as a function of input at port 1
  • Only inject one signal at a time
  • To measure S11, inject a signal at port 1 and measure its reflected signal
  • To measure S21, inject a signal at port 1, and measure the output from port 2

  • a and b  values be considered as complex  voltages representing both amplitude and phase
  • Usually we are only interested in amplitude
  • S-parameter amplitudes presented in one of two ways, linear magnitude or logarithmic based decibels (dB)
  • Formula for decibels in this case is:
  •  Sij(dB)=20 * log[Sij(magnitude)
S Parameters Matrix Representation


S Parameters are not the only way of representing networks but they are almost universally use in packaging applications
S Parameters:  Learn More
http://www.ece.ucsb.edu/~long/ece145a/Notes4_Sparams.pdf

http://rf-mw.org/transmission_lines_and_distributed_systems_transmission_lines_using_s_parameters.html