Transmission Mediums : Surface Acoustic Wave (SAW)

A surface acoustic wave (SAW) involves the mechanical transmission of a wave that travels on the surface of a material. The wave is created by a piezoelectric transducer that converts electrical to acoustic energy into mechanical vibrations that are coupled (connected) to a material that allows the wave to propagate across the surface of the material. A second transducer (e.g., a pattern of metal fingers) converts the acoustic energy back into an electrical form. Depending on the shape and type of material for which the SAW travels, the signal characteristics can be changed (such as the passing or rejecting of particular frequency bands).

A fundamental use of a SAW device is to act as a signal delay line. The relatively slow propagation velocity of the surface acoustic waves of typically 3500 m/s allows delays of several microseconds on a small chip[1]. There are many variations of SAW technology including delay lines, filters, resonators, pulse compressors, convolvers, and many more.

The first SAW devices were introduced to the marketplace in the mid-1960’s. Before the year 2000, more than 5 million surface acoustic wave (SAW) devices were being installed in electronics assemblies each day[2].

Figure below shows a transmission system that uses surface acoustic wave (SAW) technology. This device is a radio frequency filter that uses SAW technology. The radio signal is applied to an IDT. The IDT converts the electrical signal to an acoustic (mechanical) wave that moves across the surface of the SAW filter substrate. When the acoustic wave reaches the destination IDT, it is converted back into an electrical signal.

Surface Acoustic Wave (SAW) Transmission

1 comment:

Marisa said...

My name is Marisa Blankenship and I am a recruiter looking for top talent to fill a Full-Time RF Product Engineer AND RF FBAR Filter Design Engineer to be part of the Wireless Semiconductor Division of a pre-IPO Company who is a leader in Fiber Optics for Enterprise Networks and Storage Area Networks (SAN), to support the Company’s 10G family of products. These positions are based at the Company’s HQ in San Jose CA and a relocation package will be discussed with the right candidate.


1 The product engineering position supports new product development within Avago Technologies’ San Jose R&D GaAs MMIC and RF FEM design groups. The focus is New Product Introduction, NPI. Working in partnership with the R&D team, the NPI staff ensures products under development achieve their manufacturing yield targets, meet cost and performance goals and smoothly ramp into high volume production.

The NPI engineer would be responsible for managing the interface between the MMIC design groups and our GaAs PHEMT and HBT semiconductor foundries. The engineer would work with the manufacturing team to establish the operational process flow for new products through wafers level test, die prep, module assembly and final product test.
Qualifications : The candidate should have 5 years experience in the RF/Microwave semiconductor industry. BSEE degree (MSEE preferred) or equivalent. Experience with transferring RF/Microwave MMIC based products into high volume manufacturing. A working knowledge of RF/uWave/mmWave test, wafer and package level product characterization, statistical yield analysis and quality systems. Strong team leadership and communication skills are a must.

2 Join this rapidly growing team focused on RF FBAR Filters and Front End Modules (FEM) for the worldwide Cellular Handset market.

Develop innovative filters, Duplexers and multi-function modules for all handset standards such as GSM, CDMA, and W-CDMA using Avago’s new FBAR process that has world-best performance.

You will be responsible for the design and characterization of the filters, topology selection, materials used, overall specification optimization, and product transfer to manufacturing.

This process will require a balance of hands-on work in the lab and the use of simulation tools such as Agilent's ADS and Momentum.

Qualifications : Minimum Requirements:
* Masters of Science in Electrical Engineering with an emphasis on RF/Microwaves
* Five years of experience RF filter design and related fields
* Working knowledge of Semiconductor Technologies used for RF filters
* Knowledge of active RF circuit design, microwave simulation and layout tools
* Ability to work in a fast-paced, project-oriented, team environment
* Demonstrated ability to work independently, and create and meet schedules
* Strong Communication Skills

Desired Requirements:
* Ph.D. in Electrical Engineering or Physics with an emphasis on RF/Microwaves
* At least Seven years of RF filter Design Experience
* Experience with Surface Acoustic Wave (SAW) filter design

Please email me if you are interested:

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