Best SMD Wifi Module Options with Integrated Antenna

Sometimes it’s hard to think of a new consumer or commercial product that doesn’t have Wifi. Even my garage door can connect to my home network (and I suppose all my other appliances) over Wifi and can be controlled with a smartphone app. Whether you’re developing for smart homes, smart factories, or a range of other applications, your new product will need one or more wireless protocols to interact with other devices and on a larger network.

The inclusion of Wifi in most IoT products is a testament to the protocol’s massive success, but it can be difficult to ensure a small package size unless you know how to design an integrated antenna. You could go the SMA route and use an external patch or rubber ducky antenna, but the best options are to use a chip antenna or printed antenna to help keep your product small.

SMD Wifi modules are great options that can help you keep up with your development cycle, ensure a small package size, and give you a production-ready antenna. Some modules will integrate an MCU with multiple digital interfaces, Bluetooth, or other peripherals. If you want to cut down your design time with a simple SMD Wifi module, take a look at some of these component options.

Why Use an SMD Wifi Module?

Wifi is probably the best-known and most-used wireless protocol next to cellular, and there are plenty of component options you can use to build a Wifi-capable IoT product. So what are the advantages to using an SMD Wifi module instead of building out an RF front-end from separate components? First, the primary benefit depends on the designer building out the system.

Easy RF Design

Wifi modules that include integrated antennas are great for designers who aren’t familiar with the finer points of antenna design or RF routing on a PCB. This is a relatively complex discipline that spans beyond just placing an antenna connector on a board. Instead of designing a printed antenna or selecting a COTS antenna, designers can take advantage of a proven hardware solution. They also don’t need to worry about the finer points of high-frequency design, such as placement on the module and impedance matching network design.

Integration

Some Wifi modules on the market do more than just put a transceiver and antenna on a planar module. Some Wifi modules integrate other components into the package beyond a transceiver, such as:

• Standard MCU core with moderate clock rate

• Shielding around the transceiver/MCU core

• Bluetooth transceiver

• Digital control and data acquisition interfaces

Design Time and Cost

The third major benefit is in terms of overall component count and board size. An SMD Wifi module can help reduce both in a design. However, in terms of cost, an integrated SMD Wifi module can have a higher cost than buying separated components individually. If this significantly offsets design time, increases yield/quality, and simplifies some aspects of a design, then an SMD Wifi module provides real value.

Some SMD Wifi Module Options

The modules shown below are just a few you’ll find on the market, but they provide great examples of integrated SoCs with standard Wifi antenna designs directly on the module. These modules are also relatively low cost, making them useful for a range of different systems.

Würth Elektronik 2610011025000

The Calypse module from Würth Elektronik is a low-profile Wifi module operating under 802.11 b/g/n (2.4 GHz). This module can communicate with a lightweight MCU over a UART connection for applications like sensor monitoring. The Calypso module also includes a provisioning mode that allows the user to connect to a Wifi network via their smartphone or tablet with a web app. This module also includes a low-power operation sleep mode to conserve battery power in IoT products.

Texas Instruments CC3235MODAx

My favorite SMD Wifi module with integrated MCU is the CC3235MODAx from Texas Instruments. I’ve used the MODS version in multiple RF products involving new antenna and waveguide designs, but the MODAx variants integrate a PCB antenna directly on the module. TI also provides plenty of support for these modules with an SDK and design library in Code Composer, just like their flagship MCUs and other SoCs. If you want to go old-school with this SoC, TI also offers the CC3235 in a QFN variant.

These modules operate at 802.11 a/b/g/n (dual band at 5 GHz with 2.4 GHz coexistence), and they include the standard digital interfaces you’d expect to see in any great MCU (SPI, I2C, plenty of GPIOs, and UART). Other features include 256 KB RAM/1 MB Flash, 4-channel 12-bit ADC, and a Watchdog timer.

Espressif ESP-WROOM-32

The ESP-WROOM-32 SMD Wifi module is another MCU option that supports Bluetooth Classic, BLE, and 802.11 b/g/n in a single package. This component expands on the well-known ESP32 platform by integrating a PCB antenna onto a module with castellated SMD pads for easy mounting. Some applications for this module include general-purpose data acquisition, motor control, environmental monitoring, and light industrial products.

I like this module thanks to its small form factor (it’s smaller than the CC3235MODAx module shown above), yet it doesn’t sacrifice I/O count. Although you get the addition of Bluetooth, this module is not rated to 5 GHz in the product literature, although it does comply with 802.11n standards. It also includes an 18-channel 12-bit SAR ADC to support measurements from sensors or other components.

Other Components to Complement Wifi Modules in IoT Products

In addition to SMD Wifi modules, IoT products need a range of other components to function properly and interface with other devices. Some other essential components include:

• General-purpose and specialty analog amplifiers

• Processors, ADCs, and sensors

• USB PHY and connectors

• Voltage regulators for IoT products

When you need to find an SMD Wifi module for your next IoT product, you can find the parts you need and keep up with all the newest component developments when you use the complete set of advanced search and filtration features in Octopart. When you use Octopart’s electronics search engine, you’ll have access to updated distributor pricing data, parts inventory, and specifications, and it’s all freely accessible in a user-friendly interface. Take a look at our RF devices page to find the components you need.

Stay up-to-date with our latest articles by signing up for our newsletter.