News and Information from Besser Associates • February 2010
In this issue:
- Next Webcast: LTE Broadband Wireless Access
- Next Web Classroom Course: RF Fundamentals
- New Course on Modulation and Signal Formats
- Courses Coming to San Jose in March
- Tutorial: Radar Systems Basic Concepts
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Next Webcast: LTE Broadband Wireless Access
The 2010 Webinar series from Microwave Journal and Besser Associates continues with a tutorial on LTE Broadband Wireless Access by instructor Doug Morais. This free 1-hour webinar covers:
- UMTS Evolution
- Some key LTE technologies, including OFDMA and SC-FDMA
- The 3GPP LTE standard
- Mobile WiMAX standard summary
- LTE and Mobile WiMAX comparison
- Conclusion
Don't miss out on this opportunity to see the presentation and ask questions in the Q&A session that follows. Visit the Microwave Journal Webinars page for more information about the upcoming webcast, and to sign up. You can also view the recorded sessions of previous webcasts in the series.
The webinar will run Tuesday, February 16, 2010; 8:00 am PT. Visit the Microwave Journal Webinars page to view the recorded sessions of previous webcasts in the series.
RF Fundamentals Web Classroom Course June 7-11
This course provides circuit-level designers with the essential concepts needed to work effectively with high frequency electronics. Participants gain analytical, graphical, and computer-aided techniques to analyze and optimize RF circuits in practical situations. The course addresses linear active circuit design, focusing on stability, bandwidth, and noise considerations.
Learning Objectives:
Upon completing the course, the participant will be able to:• Describe RF circuit parameters and terminology.
• State the effects of parasitics on circuit performance at RF.
• Use graphical design techniques and the Smith Chart.
• Match impedances and perform transformations.
• Predict RF circuit stability and stabilize circuits.
• Design small signal and low noise RF amplifiers.
Target Audience:
Professionals required to work in high frequency domains for the first time, as well as seasoned veterans, will benefit from this comprehensive overview of practical design techniques. An electrical engineering background (or equivalent practical experience) is recommended, as well as a familiarity with complex numbers.| Monday, June 7 | 9:00 - 10:30 AM Pacific Time |
| Tuesday, June 8 | 9:00 - 10:30 AM Pacific Time |
| Wednesday, June 9 | 9:00 - 10:30 AM Pacific Time |
| Thursday , June 10 | 9:00 - 10:30 AM Pacific Time |
| Friday, June 11 | 9:00 - 10:30 AM Pacific Time |
The course is taught on-line using our Web classroom format: simply log-in to the 90 minute live conference each day right from your workplace. The instructor's audio and presentation are delivered over the computer screen and speakers. Students can ask questions at any time via the chat window - or between sessions via email. Course notes are provided electronically in pdf format. When the session is over, return to your normal work schedule without missing a beat!
| RF Fundamentals | |
| Jun 07-Jun 11, 2010 | Course 059-4273 |
| Presented by Bob Froelich | Register by 5/31/2010 and pay $449, otherwise pay $495  |
New Course on Modulation and Signal Formats
Instructor Earl McCune Jr. will be presenting a new course on "modulation without math" - or more precisely, "modulation without triple-integrals." This three day lecture and demonstration based course is designed to provide all participants with a physically intuitive understanding of wireless communication signals and why they work the way they do. With the growing impact of wireless communications on the basic operation of society, the need for a more general understanding of the basis for this technology is more important than ever.
The course approaches wireless communications signals through the window of physics and physical principles. While a solid understanding of the mathematical theory is essential for detailed system design and analysis, the fundamental choices in system application and approach are often best approached physically. Dr. McCune will not shun math in this presentation, but instead of using math as the presentation base he will instead use it as a follow up illustrator of the principles discussed.
The three days cover all of the major modulations used in digital wireless communication, including ASK, FSK, PSK, QAM, and OFDM. System principles such as an extensive discussion of the Shannon Capacity Limit, plus the physical basis of Nyquist filtering, are included. Important system parameters and analysis tools which are common to any modulation type are presented and demonstrated.
| Practical Wireless Signal Fundamentals | |
| Mar 17-Mar 19, 2010 | Course 210-4234 |
| Presented by Earl McCune Jr. | Register by 2/19/2010 and pay $1395, otherwise pay $1495 |
Course Coming to San Jose in March
Our program of RF and Wireless courses returns to the San Jose area this March 15-19. You may also be interested in our courses in San Diego, this February 22-26.
| Applied RF Techniques I | |
| Mar 15-Mar 19, 2010 | Course 001-4233 |
| Presented by Les Besser | Register by 2/19/2010 and pay $2195, otherwise pay $2395 |
| Applied RF II: Advanced Wireless and Microwave Techniques | |
| Mar 15-Mar 19, 2010 | Course 086-4237 |
| Presented by Allen Podell | Register by 2/19/2010 and pay $1995, otherwise pay $2195 |
| RF Measurements:Principles & Demonstration | |
| Mar 15-Mar 19, 2010 | Course 135-4235 |
| Presented by Al Scott and Rex Frobenius | Register by 2/19/2010 and pay $2195, otherwise pay $2395 |
| IEEE 802.11 Operations | |
| Mar 15-Mar 17, 2010 | Course 153-4236 |
| Presented by Robert K. Morrow | Register by 2/19/2010 and pay $1395, otherwise pay $1495 |
| LTE Mobile Access | |
| Mar 16-Mar 17, 2010 | Course 213-4220 |
| Presented by Douglas H. Morais | Register by 2/19/2010 and pay $895, otherwise pay $995 |
| DSP Made Simple for Engineers | |
| Mar 17-Mar 19, 2010 | Course 027-4238 |
| Presented by Rick Lyons | Register by 2/19/2010 and pay $1395, otherwise pay $1495 |
| Practical Wireless Signal Fundamentals | |
| Mar 17-Mar 19, 2010 | Course 210-4234 |
| Presented by Earl McCune Jr. | Register by 2/19/2010 and pay $1395, otherwise pay $1495 |
Radar Systems Basic Concepts
Below is a brief overview of the information featured in last month's webcast on Radar Systems.
Radar measurements can be divided into two categories: range/speed and azimuth/elevation. Range and speed measurements are relatively simple and accurate. If the target is moving towards or away from the radar antenna, the reflected signal will experience a doppler shift. This shift can be measured and the speed calculated in a straightforward manner. To measure the range of a target, a pulsed signal is sent and the time delay for the reflection is measured. Again, the range can be calculated in a straightforward manner.
A problem faced in range measurements occurs when the target is in front of another large object, such as a mountain. Then the reflection from the mountain obscures the reflection from the target. This phenomenon is referred to as "clutter," and is a significant problem for airborne radar. This is because the antenna (in a warplane) is often at a higher elevation than the target, and the reflection from the ground causes a great deal of unwanted reflections. One technique for dealing with clutter is to subtract successive sweeps from one another. The reflections from stationary objects will cancel out, leaving the moving target's reflection as the remaining signal.
"Pulse-doppler" radar systems combine range and speed measurements by sending a pulsed signal and measuring both the delay of the response and doppler shift together. Combining the pulse and doppler measurements creates a tradeoff between range ambiguity and speed ambiguity. If the pulse repetition rate is high, then the spectrum that is created has sidebands that are spread further apart from each other than if the pulse rate is low. With a high pulse rate, range measurements become more ambiguous because a second pulse may already be transmitted before the reflected signal from the target reaches the receiver. With a low pulse rate, you have more time to receive the reflection before the next pulse is transmitted, however the frequency sidebands of the signal are more closely spaced, resulting in speed ambiguity.
In azimuth and elevation measurements, the measured angle resolution is limited by the beam width of the antenna in use. In order to achieve greater accuracy, either a very large antenna is needed to shape a narrow beam, or pairs of beams can be used to reduce the uncertainty of the angle measurement. When pairs of beams are used, the antenna azimuth is changed until the reflected signal strength from both beams is equal. Essentially, the edges of the two beams are used to find the azimuth of the target.
A modern technique called Synthetic Aperture Radar involves taking several measurements from a moving station and combining the information to form a very large virtual antenna with very good accuracy. This technique can produce detailed images of subjects on the ground from a great distance away.
For more details and explanations, see the recorded session of Al Scott's webcast on Radar Systems.
