Wave Filter PCB

Wave filter PCB use a piezoelectric substrate’s acoustic resonance to magnify signals in specific frequency bands and attenuate those in other bands. This enables them to offer high selectivity.

They’re also used in medical devices to assure precise readings in ultrasound equipment and patient monitoring systems. These systems remove extraneous signals and noise and increase accuracy in a device’s operation.

Surface Acoustic Wave (SAW) Filter

SAW filters convert electrical signals into acoustic waves using transducers that vibrate on the surface of a piezoelectric substrate. This Wave filter PCB allows RF or microwave frequencies to be processed in the realm of acoustics, where electromagnetic signals can be much smaller and more precise. The result is a filter that can achieve high selectivity by focusing on desirable frequencies and suppressing undesired ones.

To create the acoustic waves, a group of input and output transducers on the surface of the substrate receives an electrical signal. These waves then travel through the acoustic resonance phenomenon, causing some frequencies to be amplified and others to be suppressed. The design and layout of these transducers is what determines the frequency response of a SAW filter.

A tunable SAW filter is used in a variety of applications, including mobile phones, GPS devices, and medical gadgets. They are known for their compact size and low insertion loss, which reduces power consumption. These filters are also frequently employed in radar systems and television receivers to remove unwanted or interference frequencies.

To make a tunable SAW filter, the input and output IDTs are connected to an RF voltage source. This causes strain to be exerted on the crystal lattice, which then vibrates. The input IDT then converts these mechanical waves into signal voltage variations. The output IDT then converts the acoustic wave back into electrical signal.

Printed RF Filter

RF filters are crucial to high-speed digital and analog signal integrity. They allow you to accept only the desired signals while rejecting unwanted ones. The RF filter’s input impedance must match the signal bandwidth, and you must also ensure that it has proper dispersion characteristics. You can achieve this by using a properly tuned printed circuit board (PCB). The RF filter’s performance depends on its structure, which is defined by the inductance and capacitance of each component. The traces in an RF filter must be routed with controlled impedance, and the best PCB design tools will evaluate your stackup’s impedance and enforce this profile as you route your RF layout.

With their unique shaping and ability to channel RF currents, a well-designed printed RF filter can deliver the right tradeoff between Q factor — a waveguide’s efficiency based on energy lost versus transmission loss — and rejection of out-of-band signals. By choosing a depressed super-ellipsoidal cavity as the basis for its RF filter prototype, Airbus Defense and Space was able to achieve a much higher Q factor than traditional designs.

The unified design environment in Altium Wave Filter PCB Supplier Designer on Altium 365 provides the digital, analog and mixed-signal tools you need to keep your productivity up while ensuring that your RF filter meets your requirements. For more information about how to create a RF filter with this industry-leading tool suite, check out the Altium Designer product page or one of our On-Demand Webinars.

Printed RF Interconnects

High-speed digital electronic devices require low interference to guarantee data transmission. The interconnect quality, base material and plating used are key factors in achieving these performance requirements. The RF connector industry has been developing new solutions to meet ever-increasing signal integrity requirements in smaller, lighter and more dense packaging.

Conventional stud-bumping via a ball bonder is inherently a serial process and can be inefficient when forming large numbers of bumps. Laser printing is an alternative to the stud-bumping process that offers higher speed, greater accuracy and lower resistivity. This method also enables more patterned contact areas and reduced board thickness, while providing the same high-frequency performance as traditional wire-bonding techniques.

This research uses laser-induced forward transfer (LIFT) to print Ag nanopaste interconnects directly onto the bond pads of an RF switch. The resulting flip-chip interconnects are then cured using a two-step process involving a low temperature pre-heat and a conventional reflow oven. High frequency measurements reveal that LIFT printed interconnects perform similarly to the RF switches that are wire-bonded, even accounting for differences between the test fixture and typical manufacturer part-to-part variation.

Optical micrographs of the top-down view and an at-an-angle view of a RF switch with LIFT printed interconnects on the Au device bond pads are shown in Fig. 4. OBIRCH measurements indicate that the printed interconnects have a relatively narrow profile that results in a resistance increase of less than 1.5% of the source voltage when compared to the device manufacturer’s specifications.

Printed RF Modules

As the world enters the Internet of Things (IoT) era, RF modules have become the key components that enable IoT devices to communicate with each other and with existing cellular networks. These standardized modules remove design complexities and reduce the overall cost of development. In addition, these pre-certified chips allow developers to focus on the end product and increase speed to market.

RF printed circuits use wave propagation to transmit and block signals on PCBs within specified bandwidths. They can also provide other functionalities, including filtering, attenuation, and amplification. The performance of these components is heavily dependent on the design of the transmission line structures and substrate material. The type of conductive ink used in the printing process also impacts sensitivity.

A RF module typically requires a power supply for its circuitry. Often, the power supply is located on the module itself to prevent emissions and maintain compliance with environmental standards. It also provides a convenient way to make connections to the host system and minimize signal-to-noise ratio.

Depending on the RF protocol used, an RF module may have one of two basic types of communication interfaces: parallel and serial. Parallel interfaces transfer data in multiple bits at the same time and include standards like USB, while serial interfaces send each bit one after another.