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Three Crucial items To Know About Transmit Receive Modules For Your Phased Array

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In this blog post you will learn 3 vital keys to transmit receive (T/R) core for your phased array. The reason this is so important is the T/R cores are used in most phased arrays. For some phased arrays the T/R core is a single chip and for others it is a highly integrated module. Regardless of the implementation, you will learn indispensable knowledge application to most of them.

T/R Key #1: Functionality

The first need to know item on T/R cores is the functionality they provide. This can be best illustrated using a a typical block diagram which is shown in Figure 1. Note how the core includes a transmit path of components including the driver amplifier and high power amplifier. Obviously, this is important since know the T/R functionality is essential to understanding them.

The receive path includes protection of the low noise amplifier which is typically implemented using a limiter and/or a switch. The purpose of receive protection is the prevent the low noise amplifier from being permanently damaged by high power signals that may enter the antenna. The low noise amplifier is the component that sets the sensitivity of the T/R core since it establishes the noise figure of the receiver.

The figure also shows the phase and amplitude functions. These are shared for the transmit and receive paths using transmit/receive (T/R) switches. The phase shifter achieves the beam steering function and the amplitude control is used for calibration and for beam pattern control.

The duplexer connects the T/R core to the antenna element.

Figure 1. Block diagram showing many of the components in a T/R core.

T/R Key #2: How Their Used In Phased Arrays

The second need to know item on T/R cores is how they are used in a phased array. For most phased arrays, a T/R core is situated at each antenna element in the array. This is illustrated in Figure 2. It shows a drawing of a 1×4 element phased array with a T/R core at each element in the array. While some arrays will have a single T/R core connected to 4, 8, or even 16 antenna elements, the functionality is usually one core function per element.

This is important since a large array of 10 x 10 antenna elements will have 100 T/R cores. As a result, the cost of the T/R core can be a large percentage of the overall cost of the array.

Figure 2. Illustration showing a 1x4 phased array with T/R cores at each antenna element.

T/R Key #3: Typical Implementations

The third need to know item on T/R cores is the typical implementations of the core functions. While there are many different possible implementations, two of the most common will be described. It is important to know these since you or your phased array partner will need to choose the implementation type for your T/R core.

The first implementation considered here is the T/R module which is fabricated with multiple but separate integrated circuits into a hybrid or surface mount module. Figure 3 is an image of an example. Note how there are many different individual integrated circuits.

The second implementation considered here is the single chip T/R. Many modern phased arrays use single chip T/R cores especially low power arrays and millimeter-wave systems. In this implementation, the T/R core is designed as a single integrated circuit or in a single surface mount package. An example is 5G milimeter-wave phased arrays.

Figure 3. Image of a T/R module used in radar systems.

There are many other need to know items for transmit receive modules used on your phased array. However, we have supplied three of them in this blog post.

If you would like to know more about how MPT can supply your next phased array solution, then reach out to us today: info@mptcorp.com or (951) 252-6336.