10.1.1 RF IC Categories10.1.2 RF Test Challenges10.2.1 Resources and Test Time Cost10.2.2 Handler10.2.2.1 Handler Types Considered10.2.2.2 Handler Types Not Considered10.3.1 Universal Test Board10.3.2 RF Test Function Sub-Circuit Design10.3.2.1 RF Power Gain/Noise Figure Detector10.3.2.2 Phase Noise and the FM Discriminator10.3.2.3 ACPR & IP3 Measurement10.3.2.4 RF & LO Source10.3.2.5 S-Parameter Measurement10.3.3 COMPLETE TEST ARCHITECTURE10.65.1 Schematic Simulation10.5.2 2.5D RF Board Simulation10.65.3 3D RF Socket and Package Modeling10.6.1 Sockets10.6.2 Wafer Probes10.6.3 Standard Wafer Probe StudyRF Testing10.0 INTRODUCTION10.1 TESTING RF IC’s10.2 RF TEST COST REDUCTION FACTORS10.3 TEST HARDWAREThere is a high level simulation, such as function blocks specifying the general parameters, or a low level simulation that includes the circuitry contained in each of the function blocks.However, some examples of test structures that do benefit from 3D simulation tools are wafer probes, sockets with non-straight pins (S-shape or J-shape), packages with non-rectangular structures or parts of the packages (bond wires). Traditional”described in this section1 RF Testing© D. Gizopoulos, Editor, Advances in Electronic Testing: Challenges and Methodologies, Springer, 2006, pp. 337-369.RF TestingRandy Wolf, Mustapha Slamani, John Ferrario andJayendra BhagatIBM10.0 INTRODUCTIONToday’s wireless communication products are increasingly complex and moreintegrated than ever before. The low prices that consumers pay for wireless phonesin a competitive market demand low-cost Radio Frequency Integrated Circuits (RFICs). The test cost has become an important factor in determining the profit margin.To economically test high volumes of RF ICs at a fraction of the IC cost, we mustadjust our existing test methods and define new test strategies. As pointed out inInternational Technology Roadmap for Semiconductors (ITRS) 2003 [1], “Customerrequirements for form factor and power consumption are driving a significantincrease in design integration levels. Test complexity will increase dramatically withthe combination of different classes of circuits on a single die or within a singlepackage. In particular, for System-in-Package (SIP) increased focus on known gooddie and sub-assembly test will be driven by the cost issue”. The commercial wirelessindustry has driven a need for very low cost RF IC’s built with very low costpackages and manufacturing processes. A key contributor to the cost ofmanufacturing an RF IC packaged part is the module final test. Up until that step inthe manufacturing process, the components can be handled in a batch mode withstandard high volume wafer fabrication and package part assembly equipment. Oncethe part hits RF test, it must be individually placed in a precision socket withprecision pressure, and electromagnetic isolation, and tested at a very narrow band,________________________________________________________bChapter 102 RF Testinghigh frequency and low signal level. The ability to mechanically handle individualcomponents and place them in a precision socket quickly and repeatable has beenaddressed by the commercial handler manufacturers with a range of efficiencies. The actual RF ICs are electrically tested with either of a rack and stack bench topequipment connected to a PC, or with commercially available Automatic TestEquipment (ATE). Usually, the most costly and complex component in these systemsare the RF receiver, or spectrum analyzer/digitizer, and the RF source(s). Figure 10-1, gives an idea of how basic ATE test cost increase when incorporating mixed signaland RF options to it. Most systems are configured to handle only one receiver persystem and up to four optional sources. Receivers must handle a frequency rangebetween 100MHz and 6GHz and have a very high dynamic range capable ofmeasuring stringent two tone signals such as Adjacent Channel Power (ACPR) orThird Order Intercept Point (IP3). These signals are difficult to measure becausethey consist of a primary high power frequency or tone at 900MHz to 6GHz which isadjacent to a very low level noise tones 10MHz away which must be measuredrepeatable to 0.1dB accuracy. The high susceptibility of the Device Under Test(DUT) to electromagnetic noise from it’s immediate surroundings and the need foran extremely sensitive, precision RF receiver to be able to make these type ofmeasurements tends prohibit parallel site testing. The sources must be capable ofproviding up to 6GHz with low phase noise and a power output between -120dBm to13dBm in .1dB steps. This chapter describes methods to address the constraints of RF testing. Itprovides a discussion of the characteristics of an RF test system that incorporatessub-circuits that can be included to the RF test board to convert the RF signal to aDC signal. This critical step has a major impact to the cost of test for an RF deviceby converting the test system from a complex RF single site tester to an extremelyfast, inexpensive multi-site DC tester. The result of this approach drives the cost oftest of these systems to that of a high throughput DC parametric tester. The sourcesare designed with high precision components while the key components, such as alow noise Voltage Control Oscillator (VCO), are designed for the frequency band ofinterest for the Device Under Test (DUT). Each successive frequency band utilizesthe same circuit board with the same VCO package. Before proceeding to the details of the test architecture, we discuss the types ofRF ICs and the tests required for them along with the challenges in developingcircuits to perform the tests: to ensure they are capable of making accuratemeasurements required by the test, and they are fast enough and repeatable to keepthe cost down for high volume manufacturing testing.________________________________________________________3 RF TestingFigure 10-1: ATE cost increase with additional mixed signal and RF features10.1 TESTING RF IC’SThere are three basic categories of RF IC’s: 1. Pure RF ICs; e.g. Low Noise Amplifier (LNA), Power Amplifier (PA), Voltage Control Oscillator (VCO), Mixer, etc.2. Combined RF / Mixed Signal ICs; e.g. Wireless LAN (WLAN), Global