LTCC Meets 5G: Advanced Filter Designs Achieve True mmWave Performance

Figure 3: S21 response for the BFCQ-3582A+ millimeter wave band pass filter supporting the 5G n260 band.

Low Temperature Co-fired Ceramic (LTCC) substrate technology is one major area of Mini-Circuits’ R&D investment. As a result of its long-term investments in materials, manufacturing processes, simulation and testing capability, research on novel circuit topologies, and world-class engineering talent, the company has developed a new series of filters based on LTCC technology that support the millimeter wave (mmWave) 5G market with a small footprint, low cost, and superior performance to competitive products and technologies. This includes the newly developed bandpass filters specifically designed for the 5G FR2 n257, n258, n260 and n261 bandwidths, low pass filters supporting bandwidths from DC up to 30 GHz and beyond, and high pass filters with passband cut-offs up to 36 GHz at the time of this writing.

A Primer on RF Semiconductors (MMICs)

A Primer on RF Semiconductors (MMICs)

A Primer on RF Semiconductors (MMICs) Radhakrishna Setty, Technical Advisor Introduction Semiconductors are ubiquitous in modern society. In addition to microprocessors for computing technologies, they are used in practically every active wireless communications system including cell phone towers, cell phones, radars and satellites to name a few. Mini-Circuits designs and produces several semiconductor-based (MMIC) components […]

LTCC Filters Enhance Differential Circuit Designs

Figure 1: Typical RF transceiver using discrete components.

Today’s analog-to-digital converters (ADC) and digital-to-analog converters (DAC) are typically differential circuit designs. Differential circuits provide many advantages over single-ended designs, including common-mode rejection of thermal noise, even order harmonics, and power supply noise and spurs. Additionally, differential circuits allow for half the voltage swing on each output compared to a single-ended design. Discrete transceivers on the other hand are often designed with single-ended, 50Ω matched components such as low noise amplifiers (LNAs), mixers and IF gain amplifiers. To interface with a differential ADCs or DACs, a single-ended-to-differential, or differential-to-single-ended, a transformer or balun is needed.

Extending the Performance and Frequency Envelope for QFN Packaging Technology

Extending the Performance and Frequency Envelope for QFN Packaging Technology

High-performance, millimeter-wave (mmW) Monolithic Microwave Integrated Circuit (MMIC) products and cost-effective surface mount lead-frame-based packaging typically don’t come up in the same conversation, and for good reason. Just two to three years ago, it was difficult to conceive of operating at frequencies above 20 GHz without considering an expensive, open cavity, High Temperature Co-fired Ceramic (HTCC) package or resorting to more bespoke chip and wire assemblies.

Reflectionless Filters Minimize Switching Transients in Wideband ADCs

Reflectionless Filters Minimize Switching Transients in Wideband ADCs

Designers are finding new techniques to improve system performance with Mini-Circuits’ patented reflectionless filters all the time. Among these, supplementing anti-alias filters in wideband ADCs to minimize the effect of switching transients has emerged as a popular use case.

Combining MMIC Reflectionless Filters to Create Ultra-Wideband (UWB) Bandpass Filters

Combining MMIC Reflectionless Filters to Create Ultra-Wideband (UWB) Bandpass Filters

Ultra-Wideband (UWB) radio is defined as any RF technology utilizing a bandwidth of greater than ¼ the center frequency or a bandwidth greater than 500 MHz [1] [2]. While UWB has been a known technology since the end of the nineteenth century, restrictions on transmission to prevent interference with narrow-band, continuous wave signals have limited its applications to defense and relatively few specially licensed operators [1]. In 2002, the FCC opened the 3.1 to 10.6 GHz band for commercial applications of Ultra-Wideband technology, and since then UWB has become a focus of academic study and industry research for a promising variety of emerging applications. To prevent interference with neighboring spectrum allocations like GPS at 1.6 GHz, the FCC has imposed specific rules for indoor and outdoor transmission of UWB signals, limiting transmissions in the permitted frequency range to power levels of -41 dBm/MHz or less.

Stabilizing Multiplier Chain Conversion Efficiency with Reflectionless Filters

Stabilizing Multiplier Chain Conversion Efficiency with Reflectionless Filters

Frequency translation devices such as multipliers and dividers are used to convert frequencies from lower spectrum regimes to higher frequencies, and vice versa. As these devices are intrinsically non-linear, they generate spurious harmonics, which are often filtered to prevent harmonics from appearing in-band. Using conventional, reflective filters creates an undesirable scenario where the out-of-band harmonics are reflected back to the multiplier. The multiplier is also affected by the reactive loading exhibited by a reflective filter at harmonic frequencies (see Figure 1). Given that multipliers have poor output return loss, this combination of effects leads to large ripples in the conversion efficiency of a multiplier chain, and hence, susceptibility to environmental factors.
This issue can be solved by leveraging the unique capabilities of reflectionless filters. To demonstrate this solution, an experiment was conducted with a doubler test circuit and a 4X multiplier chain (see Figure 2). Each experiment was conducted using comparable reflective and reflectionless filters, and the results were then analyzed.

מסנני מהוד קרמיים בעלי גורם איכות (Q) גבוה ליישומי GNSS

Spectrum Designations for GNSS Applications

מערכות GNSS (מערכות ניווט גלובלי בעזרת לוויינים) הופכות יותר ויותר להיות יישום ת”ר ((RF נפוץ הן בשימושים צבאיים וגם בשימושים אזרחיים. טכנולוגיית GNSS מוקדמת או שירותים מבוססי מיקום (LBS), פותחה באופן בלעדי לשימושים צבאיים והופעלה עם שולי שגיאה של כ-9 מ’ (10 יארד), שהיו מספקים בזמנו, אבל הם הגבילו את התאמתה לשימושי קצה שלהם נדרשה דרגה גבוהה יותר של דיוק. בזמן שחלף מאז הושקו לראשונה השירותים של מערכת GPS, לפני יותר מ- 40 שנה, התפתחות הטכנולוגיה שיפרה את הדיוק עד כדי סדר של 1.83 – 2.74 מ’. התקדמות זו של הטכנולוגיה, בשילוב עם מזעור משמעותי והפחתת עלותם של התקנים מאופשרי שירותי LBS, פתחו שוק נרחב ומתפתח של שירותי GNSS. לדוגמה, מערכת GNSS משמשת כיום בתחום החקלאות לחישובים סטטיסטיים בנוגע למזג אוויר, לתנאי קרקע ולבריאות היבול, על מנת לעזור לחקלאים להגדיל למקסימום את היבולים ואת הרווחים שלהם. חידושים כאלה עודדו את הדרישה לרכיבים שתומכים ביישומים צבאיים ותעשייתיים וביישומי צריכה.

High-Q Ceramic Resonator Filters for GNSS Applications

Spectrum Designations for GNSS Applications

GNSS (Global Navigation Satellite Systems) has become an increasingly prevalent RF application for both military and consumer use. Early GNSS technology, or location-based services (LBS), was developed exclusively for military use and operated with a margin of error of about 10-yards (9.14m), which was sufficient at the time, but limited its suitability for end uses requiring a higher degree of precision. In the time since the first launch of GPS more than 40 years ago, the evolution of the technology has improved precision to the order of 2-3 yards (1.83-2.74m). This advancement of the technology combined with significant miniaturization and cost reduction of LBS-enabled devices has opened up a large and growing commercial market for GNSS services. For example, GNSS is now used in the agricultural market to calculate statistics for weather, soil conditions, and crop health to help farmers maximize their yields and profits. Such innovations have stimulated demand for components that support military, industrial and consumer applications.

Understanding Lumped Element Filters

Understanding Lumped Element Filters

Before discussing filter designs and differentiating any given filter topology from another, it’s important to review the fundamentals of filter structures and their function. A filter is a two-port, passive, reciprocal device that allows frequencies within a given band to pass through while blocking signals outside the desired band.

There are many filter types available to the system design engineer including RLC filters, active RC filters, crystal filters, cavity filters, ceramic resonator filters and SIW, SAW and BAW filters. Filters may be fabricated using lumped elements, thin and thick film microstrip and stripline, LTCC and other manufacturing technologies. This article will focus on lumped element filters.