Quick Look
Radio-Frequency Tuner Design Advancement, 10-9318
Printer Friendly VersionPrincipal Investigator
J. Mark Major
Inclusive Dates: 05/23/02 - 09/23/02
Background - High performance software radios generally require a custom radio frequency (RF) front-end tuner for translation of radio signals to an intermediate frequency (IF) range that is compatible with the maximum sampling rates of 14-bit analog-to-digital converters. A challenging RF block tuner requirement was identified within a wideband software radio architecture used in a multi-channel Direction Finding (DF) system. The design needed to provide high dynamic range, high selectivity, low noise, and wide bandwidth, and needed to be well suited for cost-effective manufacture of several hundred units per year. Internal funding was used to mitigate risk in meeting the performance objectives within the budget and schedule constraints of the targeted program.
Approach - The primary objective was to advance the RF tuner design and to fabricate prototypes of mass-producible circuit modules. The modules are comprised of custom printed circuit boards and low-cost commercial components. The engineering effort focused on meeting the performance objectives with a low-cost design. The design was implemented using Computer Aided Design (CAD) and Computer Aided Engineering (CAE) software tools. A peer-review was performed prior to fabrication release in order to ensure quality and to avoid common problems often associated with new designs. The fabricated circuit boards were tested individually for functionality and performance and then interconnected as an electrically complete RF tuner for unit-level testing and integration with a high performance, PC-based software radio development platform.
Accomplishments - An engineering test bed of the RF block tuner, with custom circuit modules representative of the envisioned production design, was successfully produced and tested. The engineering test bed showcases SwRI's low cost, mass-producible design and provides a means to characterize performance for software radio applications that require an RF front end with high dynamic range, wide bandwidth, and low noise performance.
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The RF Module is an SwRI-designed printed circuit board assembly for the RF tuner that converts radio frequency (RF) signals down to a 7-23 MHz intermediate frequency (IF) signal space. |
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The LO Module is an SwRI-designed printed circuit board assembly for the RF tuner that generates the required local oscillator (LO) signals using Phase Lock Loop (PLL) circuits. |
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The BIT Module is an SwRI-designed printed circuit board assembly for the RF tuner that generates radio frequency tones using Phase Lock Loop (PLL) circuits for the purpose of built-in test (BIT). |
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The Engineering Test Bed showcases the SwRI RF tuner design and provides a means to characterize performance of this relatively low-cost, mass-producible design architecture, which is well suited for high-performance, wideband software radio applications. |
