A Packaged D-Band Transmitter with a Multifeed Lens Antenna Achieving 25.3dBm Single-Element EIRP for 2-D Scalable Arrays

There is a growing interest in developing D-band transceivers (TRX) [1]–[6] for wireless backhaul and high-resolution sensing applications, particularly around 140GHz due to its low atmospheric absorption. A critical design challenge at this frequency is to generate a sufficiently high EIRP while maximizing the DC-to-EIRP efficiency (η<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">EIRP</inf>), defined as EIRP / P<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DC</inf> = η<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TX</inf> x NANT x G<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ANT</inf> (Fig. 1, top). As seen from this equation, the three key factors to enhance η<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">EIRP</inf> are: (1) improving the TX circuit efficiency (η<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TX</inf>), (2) increasing the number of antennas (NANT), and (3) boosting the antenna gain (G<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ANT</inf>). While significant progress has been achieved in the D-band regarding the first two aspects, such as improving PA efficiency [7]–[8] and developing large-scale phased arrays (e.g., the 256-element array in [3] and the 64-element array in [2]), this work explores the possibility of increasing G<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ANT</inf> while keeping the array 2D beam-steerable. If G<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ANT</inf> can be increased from 5dBi (the gain of a typical patch antenna) to 19dBi (which is achieved in our prototype), a 5× DC power reduction can be achieved for the same EIRP.