We　report　on　a　prototype　graphene　radiation　detector　based　on　the　thermoelectric　effect.　We　used　a　split　top　gate　to　create　a　p-n　junction　in　the　graphene,　thereby　making　an　effective　thermocouple　to　read　out　the　electronic　temperature　in　the　graphene.　The　electronic　temperature　is　increased　due　to　the　AC　currents　induced　in　the　graphene　from　the　incoming　radiation,　which　is　first　received　by　an　antenna　and　then　directed　to　the　graphene　via　the　top-gate　capacitance.　With　the　exception　of　the　constant　DC　voltages　applied　to　the　gate,　the　detector　does　not　need　any　bias　and　is　therefore　very　simple　to　use.　The　measurements　showed　a　clear　response　to　microwaves　at　94　GHz　with　the　signal　being　almost　temperature　independent　in　the　4-100K　temperature　range.　The　optical　responsivity　reached　similar　to　700　V/W.　(C)　2018　Author(s).