Abstractâ A millimeter-wave power amplifier in 90-nm bulk. CMOS technology is described. Microstrip transmission lines with ground sidewalls are used for ...
A Millimeter-Wave Power Amplifier with 25dB Power Gain and +8dBm Saturated Output Power Yanyu Jin
Mihai A.T. Sanduleanu
Delft University of Technology, The Netherlands
Philips Research Eindhoven, The Netherlands
Eduardo Alarcon Rivero
John R. Long
Philips Research Eindhoven, The Netherlands
Delft University of Technology, The Netherlands
Abstract— A millimeter-wave power amplifier in 90-nm bulk CMOS technology is described. Microstrip transmission lines with ground sidewalls are used for signal distribution, matching and load resonators. The 3-stage PA comprises identical cascode stages with inter-stage matching. The measured peak power-gain is 25dB at 52GHz and 10dB at 60GHz with a -3dB bandwidth of 46-53GHz. Saturated output power is +8dBm with a PAE of 7%. The -1dB compression point is 5dBm. Extra process options are not used (e.g. MIM capacitors, trimmed polysilicon resistors, or thick oxide FETs). The 1180x960µ µm2 die consumes a total of 73mA from a 1.5V (± ±10%) power supply.
I.
INTRODUCTION
The rapid growth of wireless communications for broadband wireless personal area networks (WPANs), has sparked interest in millimeter-wave band operation [1] using silicon RF integrated circuits [3-10]. Other possibilities in the millimeter-wave (mm-wave) frequency range are: automotive applications, such as long-range (77/79GHz) radars for collision avoidance, security (94GHz) and extreme wide-band communication in the 120GHz band. Although operation in these frequency bands was once exclusively the domain of III-V-compound semiconductors [2] due to their superior electron mobility, higher breakdown voltage and semi-insulating substrate (107-108Ω−cm), silicon CMOS offers faster technology evolution and cost reduction at higher integration. Currently the fT and fmax demonstrated by the 90nm generation of NMOS transistors are on the order of 120GHz/280GHz, respectively, with approximately 8dB power gain in the 60 GHz band. Newer technology nodes, such as 65nm and 45nm, have better RF performance while consuming less power. The passive components in CMOS technologies (inductors, transmission lines and metal-metal capacitors) scale with the increase in operating frequency, and can complement the operation of active devices by optimizing gain over a reduced bandwidth using resonant
1-4244-1125-4/07/$25.00 ©2007 IEEE.
276
loads, for example. The combined effects of frequency and device scaling with compelling millimeter-wave application areas are driving many new research activities [3-10]. The rationale for mm-wave transceivers in baseline CMOS relates to integration and cost. Moreover, high throughput (>4Gb/s) for burst data transfers requires highspeed digital signal processing that is best realized in the fastest baseline CMOS processes. The most challenging building block in many respects is the power amplifier. Firstly, the low supply voltage in deep sub-micron processes (e.g., 1.2V) limits the saturated output power [7], while the maximum stable gain at mm-waves is just 6-8dB per stage. Multi-stage designs are therefore required in order to realize gain on the order of 20dB at mmwave frequencies. Consequently, the mixer driving the PA is allowed to have less conversion gain or even conversion loss. In the following sections, the design of a power amplifier with 24dB power gain at 53GHz and 8dBm saturated output power is described. The circuit is realized in a baseline bulk CMOS technology (i.e, CMOS090_LP), which features 6 damascene copper metal layers (5 thin + 1 thick), and low-k (
