Chip antennas offer small, compact solutions for wireless products. They often need only a few millimeters of space and a little bit of ground clearance. In return, you get performance that is slightly below that of larger antennas like flexible printed circuits (FPC), patches, and dipoles. 

Chip antennas use a dielectric resonator cavity, usually ceramic material, between two conductive surfaces to create the same function as a standard dipole antenna in a very compact space. These small devices, which are the smallest antennas available, are perfect for the high frequencies used in today’s modern communications.

The reliability and interference problems associated with being in close proximity to other components is greatly reduced with ceramic chip antennas. The chip antenna can be attached just like any other passive or active component during the surface mount assembly process and since there are no additional steps, this type of antenna is the easiest for final assembly. 

Ceramic chip antennas use matching circuits, optional ground clear areas, or a trace for coarse tuning, depending on the application. These antennas have higher performance than PCB trace antennas and they use less space. Incorporating a separate antenna offers the option of utilizing the full available height of the device, making it possible to have a 3D structure with a smaller PCB area.

Chip antennas provide high antenna-to-antenna isolation in multi-radio systems and outperform trace antennas when the optimal antenna type is selected and correctly implemented. Antenna performance always needs to be tested in the final, fully functional device using active over the air (OTA) measurements in an anechoic chamber. Some chip antennas have multiband capability and perform perfectly for five or more frequencies.

Chip antennas are perfect for many IoT applications that require a very small footprint and no external antenna.

Internal antennas are available in various forms and each type has a unique construction, function, and benefit. 

FPC
The Flexible Printed Circuit antenna is created on thin pliable material with an adhesive strip that easily can bend and be formed and adhered to the interior surface of an enclosure. The FPC antenna also includes a small cable with u.FL or SMA connector for connecting the antenna to the circuit board. These antennas are commonly used in smartphones, smartwatches, tablets, laptops, set top boxes.

PCB
The Printed Circuit Board antennas are created using traces on FR4 material with mounting tabs for vertical or horizontal implementation. Some PCB antennas come with an adhesive strip for mounting and a cable with a connector to connect to the circuit. These antennas are much larger than chip antennas and are better for lower frequencies.

Patch
The patch antenna has a low profile, which can be mounted on a flat surface. It consists of a flat rectangular sheet or patch of metal, mounted over a larger sheet of metal called a ground plane. The patch can also be made of dielectric ceramic. These antennas are commonly engineered for GPS frequencies and are available in active and passive designs.

RFID
Radio Frequency Identification antennas are a type of FPC antenna. There is a potential application in every product that can be counted, inventoried, or sold. Although inventory and point-of-sale activities comprise the lion’s share of the RFID tag applications, other designs that go a step beyond identification are growing faster. Retail products that are tagged enable not only inventory control but dynamic changes in pricing. Library books, pharmaceuticals, livestock, and airport luggage are tracked with RFID. Hospitals use them to keep track of patients, staff, medications, and equipment. Access control is enabled by keyless entry using RFID-enabled fobs and smart cards. 

NFC
Near Field Communication (NFC) is a part of the RFID technology spectrum through its unique capabilities set it apart. Strong security starts with NFCs less than 10 cm operating distance, and can be enhanced with SIM chips and cryptography. NFC was designed to be easy-to-use and to simplify other technologies as well. The widespread integration of NFC into mobile phones that began in 2011 has opened the door to many new applications. 

The rise of new digital industrial technology, known as Industry 4.0, is a transformation that makes it possible to gather and analyze data across machines, enabling faster, more flexible, and more efficient processes to produce higher-quality goods at reduced costs. 

This has increased the need for smart robotics, conveyor systems, motors, and sensors all connected together so the control system knows the exact condition or status of the entire operation at all times. This connection is typically done through wireless communication using external antennas for greater range. An external antenna is more rugged than an internal antenna and extends outside the enclosure. They have a rubber or plastic exterior for durability and some are designed with swivel connectors. 

Ceiling and wall antennas for interior office building applications often look like round discs or sticks. The typical antennas on most wireless routers are external stick dipole antennas with a swivel connector.

For applications requiring antennas in outdoor settings, special design considerations must be met in the event of harsh conditions. These outdoor antennas are used in road signage, base stations, femtocells*, smart street lights, agriculture fields and livestock farms. Many tall buildings in urban areas have cellular repeaters in densely populated areas so cell coverage can be maintained even though line of sight is not possible. 

The adoption of smart city initiatives has increased the number of outdoor antennas found in public safety, mass transit, fleet management, traffic management, rail, machine to machine, and smart grid.

5G implementation will include construction of an active multi-beam antenna system with 64 radio frequency channels and 256 antenna elements for a massive multi-input-multi-output (MIMO) application. The 5G system will include the combination of a distributed antenna system (DAS) and multiple small cell networks to cover every possible point within the coverage area.

*A femtocell is a small, low-power cellular base station, typically designed for use in a home or small business. 

Transportation is vital to our lives and livelihoods, but there is always room for improvement and innovation. With the help of dedicated short-range communication (DSRC) and vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2X) communication, all types of transportation are becoming safer, more efficient, connected, and data savvy. For starters, through DSRC and V2X technology we can drastically decrease traffic accidents, ease traffic congestion, and conserve fuel. 

These advances in safety will increase the complexity of vehicular antennas. The antennas that are found on most vehicles today have multiple functions that may include GPS, satellite radio, emergency service, AM/FM, and cellular in one sleek fin type antenna. 

Construction vehicles, commuter trains, off-road vehicles, tractors, agribots, and public safety vehicles will have the need for updated antenna technology in the near future.