Technical Articles

ARTICLES

Complex RF Mixers, Zero IF Architecture, and Advanced Algorithms: The Black Magic in Next-Generation SDR Transceivers

This paper was an Outstanding Paper Award finalist at EDI CON USA 2017

There is an interesting interaction between complex mixers, zero-IF architecture, and advanced algorithm development. The objective of this article is to establish the basic fundamentals of each: the principles of operation and the value they deliver in terms of system design, and then to discuss the interdependability of the three.


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Ultra-wideband DPD; the rewards & challenges for cable distribution systems

This paper was an Outstanding Paper Award winner at EDI CON US 2017

The first cable systems in the US started to appear in the early fifties. Even with the rapid changes in technology and distribution methods, cable has maintained a prominent position as a conduit for the distribution of data.  New technologies have ‘layered’ themselves on the existing cable network. This article focuses on one aspect of that evolution; Power Amplifier (PA) Digital Pre-Distortion (DPD), it’s a term that many involved in cellular system networks will be familiar with. Transitioning the technology to cable brings substantial benefits in terms of power efficiency and performance. With these benefits come substantial challenges; this article does a deep dive into some of these challenges and provides an overview as to how they may be solved.


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Overcoming Assembly Challenges with Bottom Termination Components

This paper was an Outstanding Paper Award finalist at EDI CON USA 2017

Bottom termination components (BTCs) have become one of the most common packages with the highest growth rate. Typical assemblies now have many of these components, often with varying types of BTCs on one assembly. What can be done when one or more BTCs start to show increased variation within the same process? Investigations have been conducted to find materials that offer the lowest voiding in large ground plane solder joints. In addition, process modifications have continually been proposed to help alleviate voiding in BTC components. These include but are not limited to: pad design, pad patterning, stencil design, via positioning, solid solder addition, and reflow profile optimization.


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Physical Size Allocations for RF Electronics in Digital Beamforming Phased Arrays

There are many challenges associated with the migration to near elemental digital beamforming for AESAs. The challenges range from calibration, digital control, distribution of clocks, LO, power, processing the volume of data and the physical size constraints of the electronics. The prolific advancement of RFICs for the wireless industry continues to enable the ability for higher levels of integration in RF designs and now practical implementations of every element digital beamforming arrays is becoming a reality. In this article, we focus on the physical size requirements for the electronics. The physical size requirements as a function of the operating frequency are discussed and practical implementation methods are reviewed. 


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