This blog is part one of a two-part series which addresses the transition for RF design considerations at lower frequencies to design considerations at mmWave frequencies, from a basic RF design perspective.
As millimeter-wave technologies continue to advance in the printed circuit board (PCB) industry, there are emerging needs for more diverse circuit constructions. A previous limiting factor for complex millimeter-wave PCB constructions, had been appropriate bonding materials to accommodate the circuit fabrication as well as the demanding RF performance at these high frequencies. These issues have been addressed in the following blog.
Circuit materials used in 5G Microwave and mmWave amps are subject to more requirements than ever before.
Choosing a high frequency circuit board material often requires weighing several factors, including cost and performance. A key starting point in sorting through printed circuit board (PCB) materials is usually the dielectric constant, or Dk, one of the essential characteristics of a laminate material and one that is subject to many comparisons among different suppliers of PCB materials.
Millimeter-wave frequency bands hold valuable spectrum for what lies ahead: fifth-generation (5G) wireless communications and automotive collision-avoidance radar systems. Signals at 60 GHz and higher might have once been thought too high to transmit and receive with affordable circuits. But semiconductor devices and circuit technologies have improved in recent years and millimeter-wave circuits are becoming standard electronic equipment in many car models.
Filter and antenna designers have long appreciated the benefits of designing distributed high-frequency circuits using defected ground structure (DGS) layouts with different types of circuit materials. As the name suggests, a DGS is a circuit in which an intentional defect or interruption has been formed in the ground plane to realize distributed forms of passive circuit elements, such as capacitors and inductors.
Much of the buzz on the show floor at the 2017 IMS in Honolulu was about millimeter-wave devices and circuits. At one time, frequencies above 30 GHz were considered “exotic” and only for military or scientific applications. But times have changed, and available spectrum is scarce.
Printed circuits for high-speed and high-frequency applications rely on fine-featured transmission lines for signal transmission. Three of the most commonly used transmission-line technologies for these applications are microstrip, stripline, and grounded coplanar-waveguide (GCPW) transmission lines.
Growing demand for mobile wireless communications services has quickly eclipsed the capabilities of Fourth Generation (4G) Long Term Evolution (LTE) wireless networks and created a need for a next-generation mobile wireless network solution. Fifth Generation (5G) wireless networks promise more capacity and capability than 4G LTE systems, using wider channel bandwidths, new antenna and modulation technologies, and higher carrier frequencies even through millimeter-wave frequencies. But before 5G wireless networks can become a reality, systems and circuits will be needed for higher frequencies than current 2.6-GHz 4G LTE wireless networks.
Woven glass is incorporated into printed-circuit-board (PCB) materials to provide structural strength. It aids the mechanical stability of a laminate, but what does it do to its electrical behavior? One of the classic concerns regarding woven glass reinforced laminate PCBs is that the “glass weave effect” can have negative impact on the electrical performance of high-speed or high-frequency circuits fabricated on these laminates. In this blog post, we examine some of the factors affecting the glass weave effect phenomenon.