11/5/2008 EECS 622 Project f08 1/19 Jim Stiles The Univ. of Kansas Dept. of EECS EECS 622 Project – A Super-Het Receiver Design Rev. A Fall 200811/5/2008 EECS 622 Project f08 2/19 Jim Stiles The Univ. of Kansas Dept. of EECS 1. Summary For this project, your team will synthesize a wideband microwave receiver design and analyze the design performance. This design includes the identification and specification of every microwave component, including LNA, preselection filter(s), mixer(s), local oscillator(s), IF amplifier(s), controllable attenuators(s), and IF filter(s). You team will submit—by 5:00 pm on Friday, December 12—a report that a) describes this design, and b) provides an analysis and verification of design specifications. Your team will not build or in any way construct this receiver—this is a paper design only! 2. Technical Requirements 2.1 Receiver Requirements The technical requirements for this microwave design are stated below. 2.1.1 RF Bandwidth The total 3 dB-bandwidth for this microwave receiver shall extend from 3.0 GHz to 5.0 GHz. 2.1.2 IF Bandwidth The instantaneous bandwidth of this microwave receiver shall be 2.0 MHz. 2.1.3 Channel Spacing11/5/2008 EECS 622 Project f08 3/19 Jim Stiles The Univ. of Kansas Dept. of EECS The adjacent signals in the RF spectrum can be as close as 5.0 MHz. In other words, the gap between adjacent signals can be as small as 3.0 GHz. 2.1.4 Selectivity The IF filter shall attenuate adjacent channels by at least 40 dB. 2.1.5 Image Rejection The RF image band shall be attenuated by at least 50 dB 2.1.6 Spurious Signal Rejection All RF signals that produce spurious products at the IF center frequency shall be attenuated by at least 25 dB. 2.1.7 Sensitivity The Minimum Discernable Signal shall be less than -104 dBm. 2.1.8 Total Dynamic Range The total dynamic range of the receiver shall be as large as possible. W/Hz f 20BW.MHz= 30f.MHzΔ= 30f.MHzΔ= 50sf.MHz− 50sf.MHz+ sf11/5/2008 EECS 622 Project f08 4/19 Jim Stiles The Univ. of Kansas Dept. of EECS 2.2 Detector Performance This output of this receiver will be attached to a demodulator with the following specifications. 2.2.1 Detector Dynamic Range The demodulator can accurately demodulate a signal if its signal power is greater than ()50minDPdBm=− but less than ()20maxDPdBm=− . 2.2.2 Detector Bandwidth The demodulator can accurately demodulate a signal if its frequency is less than 500 MHz. 2.2.3 Required SNR The demodulator requires an SNR of at least 3.0 dB. 2.3 Design Constraints These design constraints and criteria are likewise applicable. 2.3.1 Filter Bandwidth The percentage bandwidth of any and all microwave filters must exceed 0.3%. 2.3.2 Filter Order The order of every filter in the design must be less than or equal to 7.11/5/2008 EECS 622 Project f08 5/19 Jim Stiles The Univ. of Kansas Dept. of EECS 2.3.3 Filter Part Count The number of microwave filters in the entire receiver must not exceed 5 (i.e., must be 5 or less). 2.3.4 Local Oscillator Accuracy. The stability (i.e., accuracy) of the local Oscillator must be greater than +/- 3 ppm. 2.3.5 Local Oscillator Bandwidth. The percentage bandwidth of an individual Tunable Oscillator (e.g. VCO) must be less than 75%. Remember, you can combine multiple oscillators (using a microwave switch) to make a single LO. 2.3.6 Cost Receiver performance is much more important than cost, but of course we do not wish to unnecessarily increase cost. 3. Project Tasks Your team will be required to fully complete each of the following tasks. 3.1 Receiver Design Synthesis Microwave Switch LOAcos tω tuning11/5/2008 EECS 622 Project f08 6/19 Jim Stiles The Univ. of Kansas Dept. of EECS Use your knowledge of microwave components and receivers to synthesize a microwave receiver design that satisfies every technical requirement and constraint described in section 2. This includes identifying specific components (amplifiers, mixers, attenuators, switches and couplers) manufactured by microwave vendors. The exceptions to this are filters and oscillators. For the preselector filter(s), the IF filter(s), and the Oscillator(s) components, you must write a complete specification. In other words, do not select the parts from the web, but instead write a specification for these parts, suitable for submission to a component vendor. Accordingly, write a complete specification (use each and every parameter from the class handouts!), specifying values that are effective yet plausible. For example, a filter insertion loss of 20 dB would not be effective, and an insertion loss of 0 dB would not be plausible. 3.2 Receiver Design Analysis Once your team has completed its design, it must analyze the design in order to determine each and every specification of the attached Receiver Specification Sheet. This process verifies your design synthesis procedure. Effectively you should pretend that someone has given you a completed super-het design for which you know nothing other than the block diagram and each of the component specifications. In other words, pretend that you don’t know what the technical requirements were, or what decisions or procedures where used in the design synthesis. Using your knowledge of receivers only, analyze the11/5/2008 EECS 622 Project f08 7/19 Jim Stiles The Univ. of Kansas Dept. of EECS design and determine each of the receiver specifications(e.g., MDS or image rejection). For example, say we need to determine the solution to the 2nd-order polynomial: 220xx+−= Applying our knowledge of quadratic equations, we find two solutions, 1x= and 2x=− . This procedure is analogous to design synthesis—finding solutions that satisfy specific requirements or constraints. Now, we can analyze our solutions, to verify that they are correct: ()21120112022000+− =+− =−== ()()22220422044000−+− − =−−=−== Our solutions indeed satisfy the requirement! Or, using a bit more practical example, say we have some input power of ()70inPdBm=− and we need to boost this power to a value greater than -58 dBm. We thus need an amplifier with some gain G. To determine this amplifier gain we write our requirement as: ()()58inPdBm GdB+>− Therefore we conclude that our amplifier gain must be: ()()()5858 7012inGdB P dBm>− −>− − −>11/5/2008 EECS 622 Project f08