Ground-referenced current mirror with low voltage drop
A board-level design of a current mirror requires heavy emitter degeneration to ensure current matching between branches due geometric/thermal mismatch of the BJTs.

A far more common board-level current mirror is constructed with sense resistors and an opamp servoing an output current source to match/scale the reference input current. A sample schematic is shown below.



Resistor \$R_1\$ samples the reference current. Opamp \$U_1\$ drives the base of PNP \$Q_1\$ to achieve an equivalent potential at lower terminal of \$R_2\$. This feedback action forces the current through \$R2\$ to be equal to the current through \$R_1\$. 

The output current is taken at the collector. There is a small reduction in output current due to the finite \$\beta\$ of \$Q_1\$.