The antenna, in general, is not an overly complicated device in most cases. Yet, without it, our connected world would not be so connected. Just a little over a year ago, I was struggling to keep some level of normalcy after surviving the worst Hurricane in Florida’s history, in terms of sheer widespread damage. Furthermore, the only reason I could effectively use my battery-operated TV while conserving fuel in my generator was due to my antenna.
After all of the destruction around me, I was able to maintain a connection (radio and TV) to the outside world. Moreover, this was a feat worth mentioning since I could not leave my home for seven days until after I finally cut a path through the debris with my chainsaw. Although it did not take a disaster for me to understand the importance of an antenna in terms of sending and receiving data, I still welcomed the reminder even if it was under less than desirable conditions.
However, I am sure the Physicist and inventor Guglielmo Marconi, the principal inventor of wireless telegraphy, did not need a reminder of the importance of an antenna either. Because he also constructed numerous antennas for both transmitting and receiving as well as discovering the significance of taller antenna structures in the transmission of low-frequency signals. The antenna, like the devices that use them, is steadily evolving. Furthermore, with this evolution comes increased efficiency and a reduction in size. Over the next few paragraphs, I will discuss two types, Ceramic Chip & PCB Trace, of antennas in use in PCB designs and provide a comparison of their advantages as well as disadvantages.
What is a Ceramic Chip Antenna?
A Ceramic Chip antenna is a specific type of antenna vaunted for its small spatial requirements. Furthermore, these particular antennas are usually integrated into PCBs to emit high-frequency electromagnetic waves. However, they are limited in their range, which makes them ideally suited for small devices, such as WiFi routers and smartphones.
In general, Ceramic Chip antennas emit and receive electromagnetic waves just like a standard antenna, except they are much smaller in size. Also, this affords the ability to place them internally, and they are very cost-effective without sacrificing quality. Furthermore, Ceramic Chip antennas are the go-to alternative whenever a larger antenna is not plausible.
In summary, a ceramic chip antenna is one-half of the overall design considerations, and the PCB ground plane is the other. Furthermore, like a monopole antenna, a ceramic chip antenna’ s tuning, as well as radiation pattern, is dependent on the ground plane’s shape and size.
Note: Moreover, their accompanying datasheets provide radiation patterns, bandwidth, peak gain, return loss, and other parameters for the antenna. However, these parameters are in reference to the accompanying drawing, and therefore, your results may differ. Also, this is why it is essential to carefully observe the dimensions of the PCB in the accompanying drawing. Furthermore, these performance measurements are in reference to those precise ground plane dimensions. Finally, keep in mind that these measurements are from an open space observational point, and your design is most likely an internal product design.
What are the Advantages and Disadvantages of a Ceramic Chip Antenna?
The use of a ceramic chip antenna offers several benefits; for example, it eliminates the need for expensive manufacturing of new prototypes as well as limits the necessity for simulation software. This is due to the antenna’s network-tuning requirements and lack of physical properties. Overall, this is cost-effective because you are not wasting components due to repetitive prototype manufacturing.
A ceramic chip antenna offers numerous other advantages, including;
Less sensitive to component and environmental noise
Accommodates PCB design guideline changes
Requires less simulation
Easier to tune or replace
However, like almost everything else in life, there are trade-offs and adverse side-effects. In the case of the ceramic chip antenna, it comes in the form of disadvantages; they are as follows:
Increased initial cost, due to the purchase price of the ceramic chip antenna and the requirement of its supporting components. In terms of price, the average cost is between $0.10 and approximately $1.60 each, but remember this is the average cost, not the maximum cost.
The ceramic chip antenna lacks performance, slightly versus a PCB Trace Antenna
Overall, the ceramic chip antenna allows for greater tuning versatility during development since it is added to the PCB after the design phase completes. Furthermore, they accommodate expedient hardware modifications since they utilize a surface mount configuration.
Utilizing a ceramic chip antenna in your design provides more space and openness that permits the use of more components per stack. Furthermore, this translates into the use of smaller PCBs or the ability to add more components. In either case, it correlates to a more cost-effective overall design. Also, if the design is multilayered or high-volume, the savings will exponentially increase.
What is a PCB Trace Antenna?
A PCB Trace antenna is comprised of a trace drawn directly onto a PCB. Furthermore, depending on the type of antenna and your space requirements, the type of trace will vary. The examples of the types of traces in use for PCB Trace antennas include inverted F-type traces, straight traces, meandered traces, curved traces, or circular traces..
Overall, the purpose of a trace antenna on a PCB is to provide a method of wireless communication. Moreover, during the manufacturing phase of the PCB, the trace is laminated onto the PCB's surface. However, in certain instances, these traces will occupy several layers of a multilayered PCB.
Furthermore, the PCB’s trace length will determine the resonant frequency, and the higher the frequency, the shorter the trace. Also, a keep-out area is a requirement for each antenna on the PCB. Moreover, a keep-out area is a specific area around the PCB Trace antenna that does not allow the use of ground fill or copper traces on any layer of the PCB.
Small size is one of the many assets to a chip antenna.
What are the Advantages and Disadvantages of a PCB Trace Antenna?
In general, a PCB Trace antenna is challenging to implement, design, and tune, especially in a reliable and small implementation. Furthermore, like a wire antenna, a PCB Trace antenna's size is dependent on the frequencies of the target bandwidth. For example, if your design requires a low frequency, the length of the PCB Trace antenna will be much longer.
However, like a coin with two sides, the PCB Trace antenna has advantages as well as disadvantages; the following are its advantages:
The PCB Trace antenna is embedded into the PCB during the manufacturing process.
The PCB Trace antenna can operate within a wide bandwidth (if optimally tuned).
Commands a high level of strength and network reliability (if optimally tuned).
PCB Trace Antennas have a thin profile (two-dimensional).
The following are the disadvantages of a PCB Trace antenna:
Challenging to design (especially at low frequencies).
Highly susceptible to board-layout changes, thus requiring tuning after each change, or remanufacturing.
PCB Trace antennas require more space (especially at low frequencies).
The requirement of a larger PCB area increases the overall cost of the design (particularly at low frequencies).
PCB Trace antennas are predisposed to environmental interferences.
You cannot physically modify a PCB Trace antenna after the manufacturing process. Therefore, if a modification is required, you will need to change your design and remanufacture the PCB. Also, with its possibly large size and onerous nature of its tuning as well as the design process, the PCB Trace antenna promotes the use of PCB simulation (Cadence) software and extensive testing.
Making a circuit work with antennas can be a difficult process if you’re not careful.
In recent times, a designer often considered the trade-offs for their targeted frequency range and opted for a more reliable trace antenna instead of a Ceramic Chip antenna. However, with today’s trends pointing more towards smaller size and portability, the Ceramic Chip antenna is seeing an edge in the competition. As I am sure you are aware, design requirements will still dictate the type of antenna configuration that best fits your individual needs. Moreover, keep in mind that regardless of choice, trade-offs are almost always a certainty.
Working through antenna designs requires adaptable software that can adapt with quick component decisions and intensive frequency demands, but Cadence has the suite of design and analysis tools you need. OrCAD PCB Designer is the layout solution to work through all of your ceramic chip antenna questions and concerns for all of your PCB design needs.
If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts.
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