0.13-$\mu$m CMOS Phase Shifters for X-, Ku-, and K-Band Phased Arrays

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Two 4-bit active phase shifters integrated with all digital control circuitry in 0.13-<formula formulatype="inline"><tex>$\mu{\hbox {m}}$</tex> </formula> RF CMOS technology are developed for X- and K<emphasis emphasistype="italic">u</emphasis>-band (8–18 GHz) and K-band (18–26 GHz) phased arrays, respectively. The active digital phase shifters synthesize the required phase using a phase interpolation process by adding quadrature-phased input signals. The designs are based on a resonance-based quadrature all-pass filter for quadrature signaling with minimum loss and wide operation bandwidth. Both phase shifters can change phases with less than about 2 dB of RMS amplitude imbalance for all phase states through an associated DAC control. For the X- and K<emphasis emphasistype="italic">u</emphasis>-band phase shifter, the RMS phase error is less than 10<formula formulatype="inline"> <tex>$^{\circ}$</tex></formula> over the entire 5–18 GHz range. The average insertion loss ranges from <formula formulatype="inline"><tex>$-{\hbox {3~dB}}$</tex></formula> to <formula formulatype="inline"><tex>$-{\hbox {0.2~dB}}$</tex> </formula> at 5–20 GHz. The input <formula><tex>${P}_{\rm 1dB}$</tex> </formula> for all 4-bit phase states is typically <formula formulatype="inline"> <tex>$-{\hbox{5.4}}\pm {\hbox{1.3~dBm}}$</tex></formula> at 12 GHz in the X- and K<emphasis emphasistype="italic">u</emphasis>-band phase shifter. The K-band phase shifter exhibits 6.5–13<formula formulatype="inline"><tex>$^{\circ}$</tex> </formula> of RMS phase error at 15–26 GHz. The average insertion loss is from <formula formulatype="inline"><tex>$-$</tex></formula>4.6 to <formula formulatype="inline"><tex>$-{\hbox {3~dB}}$</tex></formula> at 15–26 GHz. The input <formula><tex>${P}_{\rm 1dB}$</tex></formula> of the K-band phase shifter is <formula formulatype="inline"><tex>$-{\hbox{0.8}}\pm {\hbox{1.1~dBm}}$</tex> </formula> at 24 GHz. For both phase shifters, the core size excluding all the pads and the output 50 <formula><tex>$\Omega$</tex></formula> matching circuits, inserted for measurement purpose only, is very small, 0.33<formula formulatype="inline"><tex>$\,\times\,$</tex></formula>0.43 <formula formulatype="inline"> <tex>${\hbox {mm}}^{2}$</tex></formula>. The total current consumption is 5.8 mA in the X- and K<emphasis emphasistype="italic">u</emphasis>-band phase shifter and 7.8 mA in the K-band phase shifter, from a 1.5 V supply voltage. </para>