Research On Silicon Based Millimeter Wave Amplifier Circuit For Biological Sample Detection

Since the late 1990s,terahertz medical imaging was proposed,and the terahertz frequency band has attracted wide attention as an emerging spectrum.Many domestic and foreign units have carried out relevant studies,such as skin and breast tumor edge detection,burn wound imaging,skin hydration monitoring,corneal hydration measurement,etc.Up to now,the development of portable real-time biological detection is still limited by the miniaturization of hardware.Signal generation and detection circuit based on silicon chip has become an important means of terahertz biological detection.In this paper,the amplifiers in the transceiver link of the terahertz biological sample detection and imaging system are discussed.With the design of amplifier circuit entering millimeter wave band,many problems arise.In millimeter wave frequency band,amplifier circuit design has more stringent requirements on the process,the transistor three port parasitic effect is obvious,metal wiring and silicon substrate parasitic coupling effect is significant,which makes the amplifier noise increase,gain decrease,broad Band characteristics difficult to achieve.Therefore,many novel millimeter wave technologies emerge at the historic moment.Based on silicon CMOS technology,this paper explores low noise amplifiers and power amplifiers in millimeter wave frequency band.The main research contents and achievements are as follows:1.A low noise amplifier in 34 GHz-43 GHz band is designed.The low noise amplifier has two stage of common source common gate structure,and the negative feed Back inductor is used at the source end of the common source,which increases the stability of the amplifier.The minim um noise curve(₈8)8)8)8)8)))and the maxim um power transmission curve(₁₁)are adjusted to make them conjugate,and both noise and power matching are taken into account.In the input matching network,the influence of the series and parallel structure of the capacitor and the inductor on the compression and tension of the impedance curve is explored,so as to achieve the input broad Band matching.Inter stage matching network and output matching network uses the structure of magnetically coupled resonator,and proposes two matching compensation structure,on the basis of the magnetically coupled resonator,the gain-bandwidth expansion technology expands the-3 d B bandwidth of the amplifier,and finally gives consideration to noise,gain and bandwidth.Under the premise of 23%relative bandwidth,the minimum noise coefficient is 3.8 d B,and the maximum gain is 16.3 d B.2.A 108 GHz-132 GHz power amplifier is designed.The power amplifier is a three-stage differential common source amplifier,and each stage of the differential amplifier uses a cross-coupling capacitance structure,which improves the transconductance of the amplifier and increases the linearity of the power amplifier with almost no additional noise.Due to the serious attenuation of each characteristic of the D-band transistor,in order to obtain a larger output power,the way of multiplex synthesis is adopted.The power divider and power combiner based on transformer are designed at the input and output terminals to improve the saturation output power.In order to ensure the bandwidth characteristics,a vertical laminated transformer is designed for matching between stages.Finally,the power amplifier has a relative bandwidth of 20%,a 1 d B compressed power of 9.3 d Bm,a saturation power of 13.5d Bm,a peak power add-on efficiency of 6.6%,and a maximum in-band gain of 10.4 d B.