Low power highly linear inductorless UWB CMOS mixer with active wideband input balun

Abstract

A low-power, highly linear CMOS doublebalanced mixer for UWB applications is presented. The mixer is designed based on well-known folded architecture and also benefits from DC isolation of RF (Radio Frequency) and LO (Local Oscillator) stages. Stacked NMOS-PMOS g m -boosting topology is used in the design of RF stage. To achieve very low power consumption, this stage is biased in sub-threshold region. Also an ultra-wideband active balun is designed and fabricated to generate differential inputs. The balun is separately characterized and its performance is reported both separately and together with the mixer. The design is implemented using 130 nm CMOS process and is operational from 3.1 to 10.6 GHz. The measured maximum conversion gain shows high value of 14.9 dB for the mixer core. Also, the measured double sideband noise figure has a minimum value of 7.8 dB for the mixer core and 12.9 dB when balun is added. Input (RF and LO) port matching is achieved with reflection of more than 10 dB for the entire band. Furthermore, port-toport isolation is measured that shows excellent isolation between ports. Measured IIP3 as a good indication of linearity performance is also reported and shows excellent linearity that is a result of techniques used in the design. Finally the mixer core area is measured to be 0.056 mm 2 with power dissipation of 623 µW from a 1.2 V supply.Index Terms-ultra-wideband (UWB), CMOS, Mixer, highly linear, low power, subthreshold, inductorless.

A coupled-line balun for ultra-wideband single-balanced diode mixer

“…LO power level at 7 GHz with IF=100 MHz Table 1 is the summary and comparison between the proposed mixer and other mixers based on different techniques at UWB frequency range. Thus, the advantage of this design is the implementation of coupled-line balun in UWB mixer design in order to minimize the complexity of the circuit in [16][17][18] that have been used two baluns circuit and four diodes for double balanced mixer. Another important trend is that narrow bandwidth mixers tend to have lower conversion loss in part due to the difficulty in maintaining circuit balance over the wider bandwidth, however, the single balanced mixer in [19] achieves a conversion loss around 12.5 dB and isolation of 20 dB.…”

Active Balun with Center-Tapped Inductor and Double-Balanced Gilbert Mixer for GNSS Applications

“…Narrowband systems are most often active systems that consume current and contain a resonant circuit that allows for signal filtering and additional signal amplification [1][2][3][4]. The more popular balun circuits are broadband baluns [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], among which we can distinguish the class of ultra-wideband (UWB) circuits [5][6][7][8][9]16,17]. The UWB circuits are capable of transmitting data over a wide spectrum of frequency bands with low power and high data rates.…”

“…A passive balun for the K band (18.4-32.2 GHz) composed of a pair of coupled spiral inductors has dimension of only 410 µm × 180 µm [10]. A passive balun can be implemented as a transformer [8,11,14,20,25] or as coupled transmission lines [11,18,26,27]. Balun circuit solutions using coupled transmission lines are solutions with very wide bandwidths.…”