36GHz 射頻收發器模組設計

Abstract

本論文提出了一個毫米波收發器模組設計方法，用於提供毫米波頻段(射頻) 與微波頻段(中頻)昇頻與降頻的介面。此模組包含了數個子電路，其中包括三倍頻器、38.5GHz與36GHz的平行耦合帶通濾波器、威金森功率分配器、環型混波器。我們先分別設計並量測各個子電路，待各個子電路可成功運作時將其整合與單一的電路板上(RO 4003 /8mil)。 為了方便性與避免電路性能的變動性，本模組的增益部分包括了放大器與低雜訊放大器以單晶微波積體電路方式實現。有一個外接的12.8GHz信號將被倍頻成 三倍頻接著經由濾波器濾波再經由功率放大器放大最後等功率分配作為混波器的本地訊號來源。就傳送端而言，中頻信號(2.4GHz)與本地震盪訊號經由環型混波器混波，我們取出較震盪信號低頻的部分作為射頻信號(36GHz)，接著進入影像拒絕濾波器濾除影像信號，最後以功率放大器將訊號升至足以發射的功率。就接收端而言，射頻信號從天線直接進入低雜訊濾波器，接著是影像拒絕濾波器濾除影像信號，最後射頻信號(36GHz)與本地震盪訊號經由環型混波器混波降至中頻(2.4GHz)。 最後得到的量測結果是: 輸入一個12.83GHz @ 14dBm 的本地震盪訊號可以得到3.8dB的昇頻轉頻損耗與3.8dB的降頻轉頻損耗。

A half-duplex transceiver module is designed and demonstrated for transducing the RF (36.1 GHz) and IF (2.4 GHz) signals. The module contains several sub-circuits, including an anti-parallel-diodes tripler, 38.5 GHz and 36 GHz coupled-line bandpass filters, a Wilkinson power divider, and Rat-race mixer. The sub-circuits are first designed and tested individually, and then integrated in a single printed-circuit substrate (RO 4003 /8 mils). To simplify the assembly process and reduce the performance variation, the gain stages (Pas and LNA) in the module are accomplished by using the MMICs. An external 12.8 GHz signal is fed to the module, triplied by a 12.8GHz-to-38.5GHz tripler, purified through a 38.5 GHz bandpass filter, and then enlarged by an MMIC amplifier. The resultant signal serves as the RF LO signal for the transceiver. At the transmitter end, the input IF (2.4 GHz) signal is mixed with the LO signal by using a Rat-race mixer, with the mixed lower-side-band (36.1GHz) signal extracted out through an image rejection filter. The consequent signal is then fed to an MMIC PA for transmission. At the receiver end, the input RF (36.1 GHz) is first amplifier by an MMIC LNA, filtered through an image rejection filter, and then down-converted to the IF end using the Rat-race mixer. The measurement results show that, with an input LO (12.8 GHz) signal level of 14 dBm, the module possesses an up-conversion gain of 3.8 dB and down conversion gain of 3.8 dB, which are quite similar to the simulation ones.